The length of the diagonal of a square is 50 cm, find the perimeter of the square.

Let each side of the square be x cm.

x² + x² = (50)² [Using Pythagoras Theorem]

2x² = 2500

x² = 1250

x=√1250=√(2×5×5×5×5)

x = 5 × 5 × √2 = 25√2

The side of the square = 25√2 cm

Perimeter of the square = 4 × side = 4 × 25√2 = 100√2 cm