Lenght problem

Let's start with the circle. The length of wire that was used to form the circle isn't important right now, but we're given that this piece of wire formed a circle with radius, r. Therefore, the area of the circle = Pi*(r^2).

Before we find the area of the square, recall that the circumference of a circle with radius, r = 2*Pi*r.
This circumference is, in fact, equal to the length of the wire that was used for forming the circle.
The length of wire that remains to form the square = 40 - 2*Pi*r.
Since a square has 4 equal sides, each side of the square = 1/4 * (40 - 2*Pi*r) = 10 - (Pi*r/2)

The area of a square is the product of two sides which, in this case, equals [(10 - (Pi*r/2)]^2

Looks like the answer is (E)

equate perimeters of the square and the circle to 40 -> 2Pi*r+4a=40, where a is the side of square. Pi*r+2a=20; a in terms of r will be 2a=20-Pi*r and a=10-Pi*r/2

total squares of circle and square will be Pi*r^2+(10-Pi*r/2)^2

answer e

thanks ! i got it now