Question

the following 3 shapes are made up of square, circles, and semi circles. Find the Area and perimeter of the shaded area. Write your answer as a completely simplified exact value in terms of pi

Answer 1

Perimeter = 18 + 9pi

Area = 81 - 20.25*pi

Explanation:

Perimeter = 9 + 9 + 2(2 pi r)/2 The twos cancel out.

Perimeter = 18 + 9*pi

Area of the square = 9 * 9 = 81 cm^2

Area of the 2 semicircles = 2 * pi * r^2/2

r = d/2

d = 9

r = 9/2 = 4.5

Area of the 2 semicircles = 2 (pi * 4.5^2)/2

Area of the 2 semicircles = 20.25 pi

Area of the blue figure = 81 - 20.25 pi