What is the approximate area of the shaded region?

That 10 is the diameter of the circle.

First let's find the area of the square.

A = s^2

Where 's' is the side.

A = 10^2

A = 100

Now let's find the area of the circle.

The '10' is also the diameter of the circle.

A = pi * r^2

A = 3.14 * 5^2

A = 3.14 * 25

A = 78.5

Now subtract this from the area of the square.

100 - 78.5 = 21.5

So the approximate area of the shaded region is 21.5cm^2