What is the length of the diagonal of a square whose area is 4 times of another square with diagonal as 5√2 cm?

Question: What is the length of the diagonal of a square whose area is 4 times of another square with diagonal as 5√2 cm?

Solution:
Area of square = (1/2) × (length of diagonal)²

Area of square₂ =(1/2) × (5√2)²
= 25 cm²

Area of square₁ = 4 × 25 = 100 cm²

Length of diagonal of square₁ = √(2 × area)
= √(2 × 100)
= 10√2 cm