a square and an equilateral triangle

Question

the length of a side of a square is x cm.

the length of a side of the equilateral triangle is 2cm more than the length of a side of the square.

the perimeter of the square is equal to the perimeter of the equilateral triangle.

work out the perimeter of the square.

Answer 1

the perimeter of the square is 6cm

Answer 2

The perimeter of a square is 4 times its length. Hence, the perimeter of the square is 4x. The perimeter of the equilateral triangle is 3 times its length. Since the length of the equilateral triangle is (x+2) cm, its perimeter is 3*(x+2). These two are equal, so we set the two expressions equal to one another, i.e. 4x = 3(x+2), or x = 6 cm and hence the perimeter of the square = 4*x = 24 cm