In a triangle ABC, A = 90° and D is the mid point of AC. The value of BC2 - BD2 is equal to
In the figure shown, square 2 is formed by joining the mid-points of square 1, square 3 is formed by joining the mid-points of square 2 and so on. In this way total five squares are drawn. The side of the square 1 is 'a' cm. What is the sum of perimeters of all the five squares?
D None of these