The perimeter of two squares are 68 cm. Find the perimeter of the third square whose area is equal to the different of the areas of these two squares.

a₁ = 68/4 = 17 cm
and a₂ = 60/4 = 15 cm
[ where a₁ and a₂ are sides]
According to the question,
Area of the third square = [(17)² - (15)² ]
= (17 + 15) (17 - 15)
= 32 x 2
= 64 sq cm
Let a₃ = Side of the third square.
According to the question, (a₃)² = 64 sq cm
∴ a₃ = √64 = 8 cm
∴ Perimeter of the third square = 4 x a₃ = 4 x 8 = 32 cm.