See attachment. Find area of shaded region. Try this one.

The hypotenuse is the diagonal of the square in the circle. The hypotenuse = 2•sqrt{2}. Radius = Diameter ÷ 2 R = 2•sqrt{2}/2 R = sqrt{2} The area of the circle is all that we need. A = pi•R^2 A = pi•(sqrt{2})^2 A = 2•pi Done!