Question

The side of a square is 10 meters longer than the side of an equilateral triangle. The perimeter of the sqaure is 3 times the perimeter of the triangle. Find the length of each side of the triangle.

Answer 1

represent unknowns using variables:
let x = length of a side of equilateral triangle
let x+10 = length of a side of square
*recall that perimeter of any polygon is the sum of the lengths of its sides,,
since square has 4 sides with equal lengths, and equilateral triangle has 3 sides with equal lengths:
P,square=4(x+10)
P,triangle=3x
thus:
4(x+10) = 3*(3x)

now simplify this, and solve for x.