Friday

October 28, 2016
Number of results: 146,479

**mathematics**

The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2.1.1 equation of new circle which is the rotation of original circle through 180 degree around the origin...2.1.2 find equation of another circle which is the translation (x;y)-(x-8;y-6) of the points of the ...

*March 21, 2013 by Jossie*

**mathematics**

The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2.1.1 equation of new circle which is the rotation of original circle through 180 degree around the origin...2.1.2 find equation of another circle which is the translation (x;y)-(x-8;y-6) of the points of the ...

*March 21, 2013 by Jossie*

**mathematics**

The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2.1.1 equation of new circle which is the rotation of original circle through 180 degree around the origin...2.1.2 find equation of another circle which is the translation (x;y)-(x-8;y-6) of the points of the ...

*March 21, 2013 by Jossie*

**mathematics**

The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2.1.1 equation of new circle which is the rotation of original circle through 180 degree around the origin...2.1.2 find equation of another circle which is the translation (x;y)-(x-8;y-6) of the points of the ...

*March 21, 2013 by Jossie*

**math**

can u help this the qustion is : A circle passes through the points (1,4)&(5,0) and its centre lies on the line x+y-3=0.Find (i) the equation of the circle and it parametric equations . (ii) the centre,diameter and area of the circle . (iii) the equation of the tangent at (1,4...

*December 28, 2011 by steev*

**maths**

1) Circle centre (7,-2) passes through (-2,10). Calculate radius and find equation of circle. 2) AB is diameter of circle A(9,5) B(-1,-7). Find equation of circle mid point. I know i have to use the eqn (x1+x2)/2 and (y1+y2)/2 3) Find the equation of circle with centre (-8,5...

*February 24, 2008 by Anonymous*

**steev**

can u help this the qustion is : A circle passes through the points (1,4)&(5,0) and its centre lies on the line x+y-3=0.Find (i) the equation of the circle and it parametric equations . (ii) the centre,diameter and area of the circle . (iii) the equation of the tangent at (1,4...

*December 28, 2011 by math *

**Math**

Hi guys, In the question "It is given that P (0, 3), Q(7, 5), R(9, -2) and S are vertices of a square. A circle A passes through the points P, Q, R and S. Find the equation of this circle. Hence or otherwise find the equation of circle B which is the image of A under the ...

*October 17, 2008 by Joshua*

**math**

-a circle with center at the point O(0,0) also has the point P(-2,3) on it. The equation of this circle is? and a second question: -A circle has a center of square root 5. The equation of this circle is? Please help me.

*October 9, 2008 by Garrick*

**math**

Write an equation of a circle with the center (-5,-4) and radius 6. The general equation for a circle is (x-a)^2 + (y-b)^2 = r^2, where r is the radius of the circle and (a,b) are the (x,y) coordinates of the center. Make the appropriate substitutions and you will have the ...

*May 7, 2007 by James*

**NEED MAJOR HELP! *QUADRATIC EQUATIONS***

Write the equation for the circle with center at (- 8, - 6) and radius of 10. (x+8)² + (y + 6)² = 10 (x+8)² + (y + 6)² = 100 (x-8)² + (y - 6)² = 100 Find the standard equation for the circle with center on the positive x-axis and passing through the origin with radius of 2. x...

*March 20, 2012 by Adrianna*

**Math (Pre Cal)**

Hi, I am studying for a precalculus quiz and I do not understand this hw problem: "The tangent line to a circle may be defined as the point that intersects a circle in a single point... If the equation of the circle is x^2+y^2=r^2 and the equation of the tangent line is y=mx+b...

*August 28, 2010 by Dealie*

**Math**

I need to write the standard equation for the circle that passes through the points: (-5,0) (0,4) (2,4) I have to use the general equation for a circle: x^2+y^2+dx+ey+f=0

*June 6, 2014 by Anonymous*

**calc**

a circle is tangent to the y-axis at y=3 and has one x-intercept at x=1 1. determine the other x-intercept 2. find an equation for the circle so i know two points on the circle are (0,3) and (1,0) and the equation for a circle is (x-a)^2 + (y-b)^2 = r^2 but i don't know how to...

*September 1, 2007 by sammy*

**Math (Equation of a circle)**

Find an equation of the circle with its center at (3,2) that is tangent to the positive x-axis.

*September 20, 2014 by Pao*

**Math**

This question makes reference to an orthonormal basis (i,j), and an origin O. 1. Consider the triangle ABC, with vertices A(0,-2), B(9,1), C(-1,11). Find: a) a cartesian equation of the altitude from C; b) a cartesian equation of the circle which has BC as a diameter; c) a ...

*February 27, 2008 by Anonymous*

**math**

a circle is tangent to the y-axis at y=3 and has one x-intercept at x=1 a) what's the other x-intercept b) what's the equation i have no clue how to solve this! You know that the center of the circle is somewhere in the line y = 3, denote the x-coordinate by rx. Then the ...

*August 4, 2007 by Anonymous*

**math**

Let the equation of a circle be x^2+y^2-14x+8y+56 a. Find the standard form of the circle b. Find the center of the circle c. Find the radius of the circle

*June 4, 2015 by Anonymous*

**Math**

Answer check please: Consider the circle (x-3)^2 + (y+1)^2 = 169. The point (15,4) is on the circle. Find an equation for the line that is tangent to the circle at this point. I got y= 5/12x-9/4.

*August 26, 2012 by KC*

**Alg2**

The tangent to a circle may be defined as the line that intersects the circle in a single point, called the point of tangency. If the equation of the circle is x^2 + y^2 = r^2 and the equation of the tangent line is y = mx + b, show r^2(1 + m^2) = b^2 Hint: The quadratic ...

*October 22, 2009 by Allen*

**8th grade math**

circle A has a raduis that is twice the length og the raduis of circle B. Which is an accurate statement about the relationship of these areas of circle A and B and y? a.the area of circle A is 4 times the area of circle B b. the area of circle A is twice the area of circle B...

*December 16, 2010 by Court*

**Math (urgent)**

the equation x^2+y^=25 describes a circle with center at the origin and radius 5. The line y=x-1 passes through the circle. Using the substitution method, find the points at which the circle and line intersect. a) (4,3) and (-4,-3) b) (3,4) and (-3,-4) c) (4,-3) and (-3,4) d) ...

*September 7, 2016 by Max*

**Math - Equation of the circle**

Find an equation of the circle whose endpoints of a diameter are (−3,6) and (5,−14). I tried to figure it out, but I'm not sure if my answer is correct. I got.. (x-2)^2 + (y + 4)^2 = 116 Any help would be great. Thank you!

*September 9, 2014 by Layna*

**Geometry**

Within an orthonormal system consider points A(1,4) B(5,1) C(4,8) (a)Calculate the angle ABC (b)Show that 3x+4y-19=0 is an equation for line L which passes through A and B (c)Find a vector equation for line L (d)(i)give an equation for the circle with the line segment AB as ...

*May 4, 2008 by Anonymous*

**geometry**

The equation of a circle is(x-3)squared plus (y+2)squared.The point (8,-2)is on the circle.What is the equation of the line that is tangent to the circle at (8,-2)? y=8 x=8 x=3 y=3

*January 18, 2012 by Dana*

**Geometry **

Write the equation of circle O centered at origin that passes through (9,-2) Circle B with center (0,-2) that passes through (-6,0) >For circle B, is the radius 6 in this case? So equation would be x^2+(x+2)^2=36, correct? If this is the case, how would I solve for circle O?

*March 16, 2016 by Peluche*

**equation for circle**

find the equation of a circle. the endpoints of the diameter of a circle are (3,-2) and (7,-6).

*February 5, 2012 by Declan*

**Math**

The points (4, 5) and ( 4, 1) are endpoints of a diameter of a circle. (a) Find the center of the circle. (b) Find the length of the radius of the circle. (Note that this is a distance.) Give the exact answer. Show work. (c) State the equation of the circle (in standard form...

*June 24, 2009 by Kate*

**Algebra 2**

Consider a circle centered at (2,4). What are the coordinates of the center of the translated circle if we replace x with x-3 and y with y+5 in the equation of the circle?

*January 15, 2012 by Peter*

**Algebra**

1.How do I find the center of a circle using the points (2,8) (-4,6) (1,-1) ? 2. The Radius of the circle? 3. Equation of circle THANKS!

*September 24, 2014 by Please Help!*

**geometry **

2. For the circle with equation (x 2)2 + (y + 3)2 = 9, answer each question: a) What are the coordinates of the center? none b) What are the radius and diameter of the circle? 360 c) Graph the circle.

*May 13, 2015 by toriie*

**math**

a. the line y=7x cuts the circle x^2+y^2=50 at A and B. find the coordinates of A and B. b. show that C(5;5) lies on the circle. c. show that ACB angle C=90degrees. what can you deduce about AB? d.find the equation of the tangent to the circle at C

*May 5, 2015 by Anonymous*

**geometry**

Circle O is defined by the equation x2 + (y - 2)2 = 25. Plot the center of Circle O and type in the coordinates of one point with integral values that lies on Circle O.

*August 5, 2012 by sara*

**Math**

The point (-4.3) lies on a circle whose center is at (2,1). Find an equation of this circle.

*February 5, 2011 by Adam*

**College Algebra**

using the knowledge of systems of equations, and that the equation of a circle is (x-h)^2 + (y-k)^2 = r^2, where (h,k) is the center and r is the radius. Find the equation of a circle that contains the following points: (6,2), (4,6), and (-3,5). (These 3 points each create an ...

*December 15, 2011 by Kevin*

**College Algebra**

using the knowledge of systems of equations, and that the equation of a circle is (x-h)^2 + (y-k)^2 = r^2, where (h,k) is the center and r is the radius. Find the equation of a circle that contains the following points: (6,2), (4,6), and (-3,5). (These 3 points each create an ...

*December 15, 2011 by Kevin*

**Math**

Determine whether the given equation is a circle, a point, or a contradiction (no real graph). x^2 + y^2 - 2 x - 16 y + 52 = 0 . The equation is a . (Enter "circle", "point", or "contradiction" in the answer space without quotes.)

*September 24, 2014 by irina*

**math**

circle has a center at (-8,-4) and circumference of 32.determine equation of the circle

*March 29, 2011 by Anonymous*

**Math**

If the coordinates of the center of a circle are (-3,1) and the radius is 4, what is an equation of the circle

*September 7, 2013 by Kiki*

**Trigonometry**

1) Find the coordinates of the point (-1,3) after the transformation T (to the -3,2 power) 2) What are the coordinates of point (-3,4) under D (to the 3rd power)? 3) Which of the following transformations could map the point (1,2) onto the point (3,6)? a)T (to the 2,3 power) b...

*February 24, 2010 by Tyler*

**Math**

Write the standard for of the equation of the circle that passes through the points at (0,8),(8,0),and (16,8). Then identify the center and radius of the circle.

*July 2, 2009 by Sally*

**Math**

write the equation of the circle in standard form. find the center, radius, intercepts, and graph the circle. x^2+y^2-6x-8y+25=36

*May 27, 2012 by Rachel*

**Algebra**

Find the equation for the circle with center (1,2) and passing through (-4,-3). Write the equation for the circle.

*August 26, 2016 by Jason*

**Math**

Find the equation for the following circle: The circle that passes through the origin and has intercepts equal to 1 and 2 on the x- and y-axes, respectively.

*August 8, 2008 by fishbowl*

**Math**

find the equation of the circle whose centre lies on the line 5x-2y=9 and the circle touches both the positive axes

*December 29, 2015 by Season*

**Math**

The endpoints of a diameter of a circle are (3, 4) and (7, 2). What is an equation of the circle?

*February 16, 2014 by Kiki*

**Algebra II**

In this set of eight problems, we have to match each equation with the correct description of its graph. However, these are test corrections I'm doing and I do not have the previous multiple choice answers so I can deduct from it, but can someone help me? The equation is xy = ...

*February 4, 2009 by Emily*

**math**

1. two circles. x^2+y^2-16x-8y+35=0 and x^2+y^2=5 are given. a. write the equations in the standard form. b.prove that the circles touch each other. c.hence calculate the equation of their common tangent 2. find the equation of a. circle. with centre c(2;3) and which I is the ...

*May 6, 2015 by Anonymous*

**Pre-Calc**

Can someone please be kind and show me the steps on this? Thanks Find the equation of the circle centered at the origin in the uv-plane that has twice the circumference of the circle whose equation equals (u-5)^2 + y^2 =9

*December 7, 2010 by Ann*

**Math**

A circle has a radius that increases at a rate of 10cm/s. Find the equation of the outermost circle 6 seconds after it starts to expand. Using x2 +y2=r2

*March 30, 2013 by Amjs*

**Math**

A circle has a radius that increases at a rate of 10cm/s. Find the equation of the outermost circle 6 seconds after it starts to expand. Using x2 +y2=r2

*March 30, 2013 by Amjs*

**math**

A circle has an area of 25 pi cm^2.If a circle is drawn within that circle with a diameter equal to the radius of the first circle, what is the area of the second circle? a. 2 1/2 pi cm^2 b. 4 1/4 pi cm^2 c. 5 1/4 pi cm^2 d. 6 1/4 pi cm^2 e. 7 1/2 pi cm^2 please answer and ...

*January 5, 2014 by Thomas*

**math**

HELP!! the area A of the circle in the figure can be represented by A(r)=pi,r^2 where r is the radius what are the resonable domain and range for each function? explain the problme before this made me make a equation of B(r)=5^2-pi,r^2 im not sure if there asking this or A(r)=...

*November 3, 2010 by paul*

**math (pre clac)**

so its this picture of a rectangle inscribed in a circle. the circle has a radius of 2. the vertexes of the circle are present in every quadrant, but you cant tell exactly whgat point they represent. point Q (x,y) is the vertex of the rectangle in Quadrant I and is on the ...

*April 25, 2008 by Alexis*

**math**

A. determine the equation of the circle passing through points A(3;2) B(8;12) and C(-6;-2) B. a chord of the circle x^2+y^2=50 has a midpoint at (6;3). determine the equation of this chord.

*May 6, 2015 by Anonymous*

**calculus**

There is a shape first a regular triangle inscribed in a circle, and inscribed in a square, inscribed in a circle, inscribed in a pentagon, etc. so polygon circle polygon circle, etc. the radius of the first circle is 1, find an equation for radius n. number 2:give an argument...

*February 22, 2016 by Andre*

**Equations of a Circle**

Write the standard for of the equation of the circle that passes through the points at (0,8),(8,0),and (16,8). Then identify the center and radius of the circle. I have r=8, center=(8,8). What now?

*April 21, 2012 by Some1 Help Me Plz*

**GEOMETRY**

The diameter of a circle has endpoints P(10, 2) and Q(4, 6). a.Find the center of the circle. b.Find the radius. If your answer is not an integer, express it in radical form. c.Write an equation for the circle.

*May 30, 2012 by HELP PLEASE!*

**geomtry**

A diameter of a circle has endpoints P(-10,2) and Q(4,6) a. find the center of the circle. b. find the radius of your answer is not an interger express in radical form c. write an equation for the circle

*May 22, 2015 by gavin*

**maths**

Given that the equation of the circle is x^2 + y^2 +2x -8y+5 =0 (i)Find the centre and radius of the circle (ii)Determine whether the line x-3y=8 is tangent to the given circle

*February 27, 2012 by mazoe*

**maths**

Given that the equation of the circle is x^2+y^2+2x-8y+5=0 (i)find the centre and radius of the circle (ii)Determine whether the line x-3y=8 is tangent to the given circle

*March 14, 2012 by tembo*

**maths-urgently needed**

find the equation of circle if the line 2x - y +1 = 0 touches the circle at the point (2,5) and the center of the circle lies on the line x+y -9 =0

*February 14, 2013 by Anonymous*

**Math**

Circle O is centered at the origin and has a radius of 5. Circle O' is the image of circle O after a translation of T1,2. What is the center of circle O'? What is the radius of circle O'?

*March 3, 2010 by Collin*

**Gradient of circle?**

A circle has the equation x^2+y^2-4x+6y-12=0 and i have already found that the centre has a coordinate of (2,-3), and a radius of 5 units. But i need to find points on the circle that has the gradient of -4/3 when a tangent is drawn on the point. How do i do that???

*September 26, 2009 by Marrion*

**summer math hw **

one circle has a diameter of 10 inches. a second circle has a diameter that is twice the diameter of the first circle What is the ratio of the area of the smaller circle to the larger circle

*August 31, 2014 by lesleyy *

**Geometry**

The equation of a circle is (x−4)^2+ (y+2)^2=16. B) Find the radius of the circle with the given equation. Can somone give me step by step explanations? Thank you in advance!

*May 25, 2014 by Jazy*

**geometry**

This one is confusing me. please help The diameter of a circle has endpoints P(10, 2) and Q(4, 6).Find the center of the circle.Find the radius. If your answer is not an integer, express it in radical form. Write an equation for the circle. Thanks

*January 12, 2012 by ryan*

**Math**

how an I tell if this is a circle or an ellipse? also, how am I supposed to solve it? -x^2+2y^2+8x+3=0 I answered a similar question for Jordan last night at 11:20 divide your equation by -1 to make it start with a positive x^2 term. At this point you should realize that it is...

*April 4, 2007 by Darrin*

**Math (geometry)**

Line l is tangent to circle O at point P(3,4) where the center is located at (0,0). a. Find the radius of the circle. (I got 4) b. Give an equation of the circle. (I got x^2+y^2=16) c. Find the slope of line l. d. Give an equation of line l...

*April 30, 2008 by Emily*

**math**

A circle is tangent to the y-axis at y=3 and has one intercept at x=1. a) Determine the other x-intercept. b) Find the equation of the circle. Thanks for helping!

*August 3, 2008 by alk*

**algebra**

1)Write an equation for the parabola with focus (1,3)and vertex(0,3) answer= x= 1/4(y-3)^2 2)Write an equation for a circle if the endpoints of a diameter are at (1,1)and(1,-9) answer= (x-1)^2+(y+4)^2=25 3)Which is the equation of a circle with center (0,1)and radius 2 units? ...

*August 21, 2007 by Marissa*

**Math**

I have a series of questions that I did. They lead up to the last question I can't solve. Could you check my math and help me with the last question? Thanks! a) Let a be the point (2,3). Compute the distance from Origin 0 to A answer: a^2 + b^2 = c^2 3^2 + 2^2 = c^2 c=sqrt(13...

*October 14, 2010 by Shane*

**Math**

A circle is tangent to the y-axis at y=3 and has one x-intercept at x=1, find the other x-intercept and the equation of the circle. ...And if it's not any trouble, could you please explain how to do get there alongside showing me what to do? Thanks (:

*February 8, 2010 by Leslie*

**math**

The circle touches x-axis at (3,0) and intercepts y-axis with 8 units.Find the equation of circle.

*January 10, 2016 by kishor*

**math**

1. A(-3;4) is a point on a circle with centre at the origin. a.determine the coordinates of B, if AB is a diameter. b. Show that point C(0;5) lies on this circle. c.show that ACB has a magnitude of 90degrees. 2.a.ddetermine the equation of the circle with AC as diameter, if A ...

*May 4, 2015 by Anonymous*

**math - geometry**

Austin wants to sketch the graph of a circle represented by the given equation. (x - 4)2 + (y + 7)2 = 64 Using complete sentences, describe the steps used to sketch the circle on a coordinate grid

*August 19, 2013 by kris*

**Check!!!**

okay so the question is: A unit circle center at the origin undergoes a series of transformations. The equation of the resulting graph is (x-3)^2+ (y+4)^2= 25 describe the transformation the unit circle underwnt Answer: The original circle was centered at the origin and had ...

*February 14, 2007 by math*

**Pre-Calc (Circles)**

Describe the conditions necessary, where circle A has a larger radius than circle B, for the two circle to have no points of intersection, while circle B is entirely in the interior of circle A.

*November 17, 2009 by Anonymous*

**math-equation of circle**

Write the standard form of the equation of the circle that passes through the points at (4,5) (-2, 3), and (-4,-3). a. (x-5)^2+(y+4)^2=49 b. (x-3)^2+(y+2)^2=50 c. (x+4)^2+(y-2)^2=36 d. (x-2)^2+(y+2)^2=25 I'm having trouble with solving for the variables...after I make the ...

*May 13, 2008 by Lisa*

**math**

The circumference of a circle varies directly from its diameter. If the circumference of the circle having a diameter of 7cm is 7 cm, what is the circumferences of the circle whose diameter is 10cm? 18cm? 20cm? a. Write a mathematical statement that relate two quantities ...

*August 21, 2014 by =)*

**math**

The equation of a circle with centre O(0,0) is x^2+y^2=40. The points A(-2,6) and B(-6,-2) are endpoints of chord AB. DE right bisects chord AB at F. a)Verify that the centre of the circle lies on the right bisector of chord AB. b)Find the distance from the centre of the ...

*October 9, 2008 by Cynthia*

**Math**

The circumference of a circle varies directly from its diameter. If the circumference of the circle having a diameter of 7cm is 7 cm, what is the circumferences of the circle whose diameter is 10cm? 18cm? 20cm? a. Write a mathematical statement that relate two quantities ...

*September 19, 2015 by Jennylyn*

**Math**

These questions that I have completed are on a test review for my exam and I would just like to know if they are correct. These are only a few of the questions, I have more that are just not complete yet. Thank You! 1) List the intercepts for the graph of the following ...

*October 6, 2010 by Hannah*

**math**

Two chords in a circle are equal in lengh.The distances from the centre of the circle can be represented by x2 and 4x respectively.How far is it chord from the centre of the circle?[Under the topic of properties of a circle.]

*January 19, 2016 by Gift*

**Math(Please check answers)**

These questions that I have completed are on a test review for my exam and I would just like to know if they are correct. These are only a few of the questions, I have more that are just not complete yet. Thank You! 1) List the intercepts for the graph of the following ...

*October 6, 2010 by Hannah*

**math **

Rewrite the following equation in the center-radius form of the equation of a circle. x2 - 2x + y2 + 2y - 2 = 0

*March 21, 2014 by Elizabeth*

**math**

A circle with the equation (x + 4)2 + (y - 3)2 = 9 is reflected over the line y = -1. What is the equation of the image?

*January 22, 2012 by Callie*

**Geometry**

The equation of a circle is x^2 + 6x + y^2 - 2y = 15. What are the center and radius of the circle? Please show work.

*May 3, 2011 by Anonymous*

**Algebra**

The point (-1,0) lies on a circle whose center is at (-6,5). Find an equation of this circle

*May 17, 2011 by Jennifer*

**maths**

the equation of the circle is x^2+y^2+2x-8y-1=0. Find the coordinates of the point where the circle crosses the x-axis

*March 30, 2012 by mumba*

**geometry**

Given the equation of the circle (x 9)2 + y2 = 484 , where is the center of the circle located at?

*November 12, 2013 by jose*

**Algebra**

Write the equation of the circle. Center at (4,2) and the circle passes through the point (-1,-1). Please help!

*September 23, 2009 by Bree*

**circle**

Find the equation to the circle which has its centre at the point (3,4) and touch the straight line 5x 12y=1

*July 25, 2015 by siddharth*

**Geometry**

Find the equation of the circle which is concentric with the circle x^2+y^2+3y-8y+16=0 and tangent to the line 4x+3y-12=0. Show your solution.

*August 31, 2016 by Vince*

**Calculus**

Points (1, 6) and (3, 2) are endpoints of the diameter of a circle. (a) What is the exact length of the diameter? (Simplify as much as possible) Answer: ________ (b) What is the center of the circle? Answer: ____________ (c) What is the equation of the circle? Answer: ...

*March 10, 2012 by Brian*

**Algebra**

If a circle of radius 5 is made to roll along the x-axis, what is the equation for the path of the center of the circle?

*August 11, 2009 by coried*

**Algebra**

The circumference,y, of a circle varies directly with the diameter,x, of the circle. Write an equation if y=44cm when x=14cm.

*May 17, 2010 by Austin*

**Pre-Calc**

True or False: Every equation of the form X^2+y^2+ax+by+c=c The radius of the circle x^2+y^2=9 is 3 The center of the circle (X+3)^2+(y-2)^2=13 is (3,-2)

*January 10, 2012 by nelly*

**Algebra ll**

Help please The center of a circle is at (-5 , 1) and it has a radius of 9. What is the equation of the circle? A.(x-5)^2+(y+1)^2= 81 B.(x-5)^2+(y+1)^2= 3 C.(x+5)^2+(y-1)^2= 81 D.(x+5)^2+(y-1)^2= 3

*June 6, 2014 by Me and I*

**math **

I am supposed to find the area of a segment of a circle. The circle is cut with two radi with an angle of 90 degrees. Then where the radi touch the circle another line is drawn to connect them. The triangle and the small section between the triangle and the edge of the circle ...

*May 4, 2013 by Ed*