One-Of-A-Kind Puzzle For The Math Whiz

   

                                                           

The figure shown above contains four squares which are arranged such that:

i) No two squares overlap, only touch at corners

ii) Squares A and C touch B and D, but not each other.

iii)Squares B and D touch every other square.

iv) Squares A, C and D each have a corner on a common line.

Show that the length of a side of square B is twice the length of a side of square D.

Solution will be posted by the end of the week.