Question

In the figure above the equal lateral polygon ABCD EF is inscribed in a circle if the length of the Arc. AFE is 10 pi find the length of the radius of the circle

Answer 1

Arc AFE is 1/3 the circumference of the circle, so has length (2πr/3).
.. 2πr/3 = 10π
.. r = (3/2)*10 = 15

The radius of the circle is 15 units.