Question

what is the area of the square minus the area of the circle

Answer 1

Can you explain a bit more?

Answer 2

The area of the circle is πr2.

From the diagram, the side length of the square is 2r.

Hence the area of the square is (2r)2 = 4r2.

you could find the ratio area circle/area square = πr2/4r2 = p/4. As a percentage this is 100π/4 = 78.54%.

Alternatively they may then subtract the area of the circle from the square area to find the wasted area.

4 r2 - πr2 = r2 (4 - π). The percentage wasted is then 4 - π/4 = 21.46%