Related Rates - A circle is inside a square.

Question

A circle is inside a square.

The radius of the circle is increasing at a rate of 1 meter per minute and the sides of the square are decreasing at a rate of 5 meters per minute.

When the radius is 6 meters, and the sides are 15 meters, then how fast is the AREA outside the circle but inside the square changing?

The rate of change of the area enclosed between the circle and the square is

____ square meters per minute.

Answer 1

(One tiny note - I drew the picture such that the circle fit *perfectly* inside the square... this isn't necessary the case - it just happened to be how I drew the picture.)