In the figure below, a circle is inscribed in a square with side b and a square with side a is inscribed in the circle. What is the area of the square with side b?
(1) a = 4
(2) the radius of the circle is 2 radical sign 2
Visualizing the diagram that:
The diagonal of the small square = diameter of the circle = the side of the bigger square.
From 1, b = the side (b) of the bigger square = diameter of the circle (d = 2r) = a (sqrt2) = 4 (sqrt2). Sufficient.
From 2, If r = 2 (sqrt2), d = 4 (sqrt 2), which is equal to the side (b) of the bigger square. Sufficinet..
So it is D..