Question

A circle is placed in a square with a side length of 18 mm, as shown below. Find the area of the shaded region.

Answer 1

Answer: the shaded region = 69.66mm^2

Explanation:
Assume shaded region is X
Then :
X + Area of circle = area of square
X = area of square - area of circle

Find area of square:
Side length = 18mm
Area = 18 x 18 = 324

Find area of circle:
Side length of a square = the diameter of the circle = 18mm
And r(radius) = d/2 = 18/2 = 9
Area = pi x 9^2 = 254.34

Now find X
X = 324 - 254.34 = 69.66