Answer:
10 inches
Explanation:
Given the side length if ABCD = 20 inches.
The midpoint of the sides ABCD implies the point that divides each of the sides into two equal parts.
Midpoint of side AB = BC = CD = AC =
= 10 inches
So that, the side length of the square to be formed by joining the midpoints of the sides of ABCD is 10 inches.