Answer:
The length of the arc is 10 pi
Step-by-step explanation:
Mathematically, the length of an arc is calculated as;
theta/360 * 2 * pi * r
theta represents the central angle subtended by the arc which is a right angle according to the question (a right angle is 90 degrees)
r is the circle radius which is 20 inches
so we have the length of the arc as;
90/360 * 2 * pi * 20 = 40 pi/4 = 10 pi