Question

Question 3 options:

In an equilateral triangle, all 3 sides are equal length, and the perimeter of an equilateral triangle is 3 times the length of one side.

If one side measures 9 + 3x, and the measure of another side is 5x – 5, what is the perimeter of the equilateral triangle?

Answer 1

90

Explanation:

Given: Measure of one side of equilateral triangle =
`9+3x`

Measure of another side of equilateral triangle =
`5x-5`

In equilateral triangle all three sides are equal in length.Therefore,

`5x-5 =9+3x`

`5x-3x=9+5`

`2x=14`

`x=(14)/(2) =7`

On substituting the value of x in side of equilateral triangle,

One side of equilateral triangle =
`5x-5=\left (5(7)-5 \right )=(35-5)=30`

Perimeter of equilateral triangle = 3 ( length of one side) ........( given)

perimeter of equilateral triangle =
`3*30 = 90.`