if the side of a square be increased by 4 cms. The area

if the side of a square be increased by 4 cms. The area increased by 60 sq. cms . The side of the square is ?

Let each side = x cm
Then, (x + 4 )² - x² = 60
⇒ x² + 8x + 16 - x² = 60
∴ x = 5.5 cm