Help!

Let a, b, and c be complex numbers. Let a1 be the image of a when it is rotated 90 degrees clockwise around b. Let a2 be the image of a1 when it is rotated 90 degrees counter-clockwise around c.



Then a2 can be written in the form a2=pa+qb+rc
for some complex numbers p ,q , and r. Find p^2+q^2+r^2.

 

Thanks everyone! This problem is soooo hard for me :(

BasicMaths