Question

The rectangle in the figure below is inscribed in a circle with a radius of 5 radical 5. If the height of the rectangle is twice its base, what is the area of the rectangle.
A)2
B)3
C)4
D)5
E)6

Answer 1

So far I got the diagonal of the rectangle is 10 radical 5. Not sure what to do next

Answer 2

This is what i got so far