+0

# Perimeter of a triangle.

+1
29
5
+53

If I am attempting to find the perimeter of a triangle in which the side lengths given are 7x centimeters and 5x + 16 centimeters what is the last side length

OwenT154  Sep 13, 2017
Sort:

#1
+351
0

Does it give the perimeter?

Gh0sty15  Sep 13, 2017
#2
+53
0

No it does not.

OwenT154  Sep 13, 2017
#3
+351
+1

Does it say what kind of triangle this is?

Gh0sty15  Sep 13, 2017
#4
+53
0

yes equalateral

OwenT154  Sep 13, 2017
#5
+351
+1

Ok then. I got the answer.

In an equilateral triangle, all the side lengths are the same.

So that means 7x = 5x + 16.

Subtract 5x to both sides to get 2x = 16.

Divide both sides by 2 to get x = 8.

But that's not our answer. We need to plug in 8 instead of  x to one of the 'sides equations.'

Let's plug it into 7x.

7(8)  = 56. Remeber, we substituted 8 for x.

So we know a side of the equilateral triangle is 56 cm.

And we know that all the side lengths are the same.

So the last side length would be 56 cm.

Gh0sty15  Sep 13, 2017

### 9 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details