Question

CD is the Diameter. The measure of Arc CD is 11x Find the length of the radius in the circle.

Answer 1

11

Explanation:

Using S = rA, where S is arc length, r is radius and A is angle(in radians).

Comparing: S = 11π, A = 180° = π

=> 11π = rπ

=> 11 = r

Required radius is 11 unit

Method 2:

This is a semi circle, circumference of semi circle is πr, so

πr = 11π

r = 11