Question

Find the area of the biggest possible square that would fit into a circle having a radius of 3cm.

Answer 1

The largest square that can fit in a square of radius 3cm can have its diagonal length twice its radius.
But diagonal of a square is root square root of {2} x length of each side.
Hence from above, diagonal length is 6 cm and so, the side can be 3*(2^1/2) 
So area of square is (3*(2^1/2))^2 = 18 cm^2