Question

Prove that the sum of the squares of the sides of a rhombus is equal to the sum
of the squares of its diagonals.​

Answer 1

Use the pythagorean Theorem.

The square of each side is equal to the sum of the squares of each diagonal, divided by 2.

${a}^{2} = { \frac{d1}{2} }^{2} + { \frac{d2}{2} }^{2}$

Now add each case .

Hence Proved.