math

posted by .

Whats the difference between an arc [of a circle]'s length and measure? And how do you find each of them?

The "measure" of an arc is the angle that it subtends from the center of the circle. Call that angle A.

The length of the arc is
2 pi R * [A/(2 pi)] = R*A, if A is in radians and R is the radius of the circle, or pi R*A/180, if A is measured in degrees.

Emily think of a pizza that has been cut into 8 equal pieces, and look at one of those pieces.

The arc measure would be the angle that your piece of pizza has as its point, in this case 45º
The arc length would be the length of the curved part of your pizza slice, in this case 1/8 the circumference of the pizza
(remember C=2*pi*r)

  • math -

    6.3

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Geometry

    The question is to find the measure of arc PQ in Circle A. The point A is the center of the circle, and the chords PR and SQ intersect at the center. Arc PQ is (3y-10), while arc SR is (2y+20). I know there's a theorem that states …
  2. Math

    I think this will be the last one. Find the radius of circle C if the measure of anglePQR=24° and the length of arc PR is 8pi. Answers: a.15 b.20 c.30 d.60 e.45 The diagram looks like a circle with its center at C. At a point on the …
  3. trigonometry

    Find the length of the arc that subtends an angle of measure 70 degrees on a circle of diameter 15 centimeters.
  4. Precalculus

    The figure shows part of a curve traced by a point on the circumference of a circle of radius 4 that rotates, without slipping, around a fixed circle of radius 2. The rotating circle starts with angle t = 0 radians and the point P …
  5. geometry

    Point C is the center of the circle. The measure of angle ACB is 15x + 20. Arc AB measures 20x – 10. Find the measure of arc AB.
  6. maths

    an arc of a circle subtends a central angle of 5pi/6 radians.if the radius of the circle measures 10.6cm, determine the approx measure of the arc leanth
  7. math advanced functions

    a) Determine the measure of the central angle that is formed by an arc length of 5 cm in a circle with a radius of 2.5cm. Express the measure in both radians and degrees, correct to one decimal place. b) Determine the arc length of …
  8. math

    An angle of 1.8 radians at the center of the circle subtends an arc of length 23.4cm. Find: (a) The radius of the circle (b) The area of the sector enclosed by the arc and the radii.
  9. algebra

    The area of a circle is 78.5 square centimeters, and a subtending arc on the circle has an arc length of 6pi. The estimated value of is 3.14. what is the measure of the angle subtended by the arc in degrees?
  10. apex geometry

    Hannah constructed two similar circles as seen in the image below. If the arc length of the larger circle is , which of the following would be true?

More Similar Questions