Let the side of the square be a.
∴ Area of a square = (side)2 = a2 New side of the square = 3 × a = 3a
∴ New area of the square = (3a)2
= 9a2
= 9 × area of original square
∴ If the side of a square is tripled, its area will become 9 times the area of the original square.