The angle of a sector of a circle is 90 degrees. Find the exact area of the sector if the circle has an area of 20 pi in squared.

Question

This is a geometry question involving area and sectors of circles. 

Answer 1

Do you see (in your mind's eye, or in a drawing that mimics the words) that this is one quarter (90/360) of the entire circle?  So one fourth of 20(pi) must be 5(pi) square inches.