Homework Help: Geometry

Posted by Temperance on Monday, June 14, 2010 at 12:59am.

What is the circumference of the circle if the radius is:
5x-My answer was 57(x)pi.

What is the radius if the circumference is:
30x(pi)-My answer was 2x.
(x + y)pi -My answer (x+y)/7.
What is the length of the arc if:

radius=3 degree of measurement of arc=6- My answer was pi/9.
radius=4 degree of measurement of arc=7- My answer was 9(pi)/18.
radius=2 degree of measurement of arc=x- My answer was x(pi)/15.

My answers for these questions were incorrect. I am unsure of how to redo them.Cheers!

Geometry - Reiny, Monday, June 14, 2010 at 6:45am
1. circumf = 2πr
= 2π(5x) = 10πx

2. using the above ...
30xπ = 2πr
r = 30xπ/(2π) = 15x

3. arclength = rŲ , where Ų is the central angle in radians

if r=3
if arcangle =6° , then Ų = π/30

(to change ° to radians, multipy your degree unit by π/180) ..... 6(π/180) = π/30

so:
arc = 3(π/30) = π/10

The others in this third part of your post are done the same way

Answer this Question

Related Questions

Computer Science (Basics) - public class Circumference { /** * @param args */ ...
math - the radius of a circle when the numeric values of the circumference and ...
Algebra - The Circumference and area of a circle of radius r are givin by 2 [pie...
Geometry - I need help on a problem thats on formula for circumference. A circle...
math - how do i get the area of a circle????????????? area of a circle=pi * ...
math - how do you find the diameter of a circle if you don't have the radius...
Circumference,Radius, Diameter - The circumference of a circle is 12.56 ...
maths - O is the centre of the circle and A and B are points on the ...
math - HELP!! the area A of the circle in the figure can be represented by A(r)=...
Math--need help fast - If the radius of a circle is x/6, what's the diameter...

For Further Reading

First Name:
School Subject:
Answer: