You are given a rectangle that is placed around a semicircle. You are also given the width of the rectangle that is 8cm. You are asked to find the area of the shaded region. Let us assume that the semicircle is inscribed in the rectangle or inside the rectangle so that the diameter of the semicircle is the same as the side of the rectangle. Let us also assume that the shaded region are the ones not inside the semicircle.
Area of a circle = πD²/4
Area of a circle = π(8cm)²/4
Area of a circle = 16π cm²
Area of the rectangle = LW
Area of the rectangle = (8cm) ( 4cm)
Area of the rectangle = 32 cm²
Area of the shaded region = 16π cm² - 32 cm²Area of the shaded region = 18.265cm²