Question

Two sides of a triangle have the same length. the third side measures 2 m less than twice the common length. the perimeter of the triangle is 14 m. what are the lengths of the three​ sides?

Answer 1

To find the perimeter you would add all the sides of the triangle together.  Represent the length of each side using the information given.

1 side =  x
2 side = x
3 side = 2x - 2

Add these together and combine the like terms.

x + x + 2x -2; the bold parts are the like terms

4x - 2 represents the perimeter.