Question

A triangle has a perimeter of 13x-21 units. One side is 4x+3 units. The other side is 5x-8 units. Write an expression to find the missing side.

Answer 1

4x - 16

Explanation:

A triangle is a three sided polygon with three edges and three vertices. the sum of angles in a triangle is 180 degrees

the perimeter of a triangle = sum of the side lengths

let the unknown length be represented with y

13x - 21 = 4x + 3 + 5x - 8 + y

13x- 21 = 9x - 5 + y

Make y the subject of the formula

13x - 21 - 9x + 5 = y

4x - 16 = y

the side length = 4x - 16