A square sheet of paper has each side measuring 20 cm. Two semicircles are drawn on opposite sides of the square, using those sides as diameters. If the semicircles are cut out, what is the area of the remaining paper?

Explanation

The area of the square is 20 × 20 = 400 cm². Each semicircle has a diameter of 20 cm, so the radius is 10 cm. The area of one semicircle is (1/2) × π × 10² = 50π cm². Since there are two semicircles, their combined area is 100π cm². Subtracting this from the square's area, the remaining area is 400 – 100π cm².