Qt A

\((x+y)^2\)

The triangle is a right angle so we can apply the Pythagoras Theorem.

\((x+y)^2\) = \((a+b)^2\) + \((c+d)^2\) = \((a)^2\) + 2ab + \((b)^2\) + \((c)^2\) + 2cd + \((d)^2\)

= \(a^2+b^2+c^2+d^2\) + 2 ( ab + cd )

Qt B

\(a^2+b^2+c^2+d^2\)

As a , b , c , d are sides of a triangle, they will be positive so Qt A is greater than Qt B

Answer A