Question

HELP PLZ!!!

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

Check the picture below.

Answer 2

The perimeter of the equilateral triangle is 90 units.

Explanation:

Let the side of the triangle be = s

So, perimeter of equilateral triangle =
`s+s+s=3s`

One side measures 9+3x and the measure of another side is 5x-5.

Both are equal, so we get the sides as:

`9+3x=5x-5`

`3x-5x=-5-9`

`-2x=-14`

x = 7

We get the sides as :

First side
`9+3(7)`

= 30

OR

Second side
`5(7)-5`

= 30

And the third side will also be 30 as it is equilateral triangle.

Hence, the perimeter is =
`30+30+30=90` units

Therefore, the perimeter of the equilateral triangle is 90 units.