Question

The perimeter of a triangle is 20 cm. The lengths of the sides are x, x + 3, and x + 5.

What is the length in centimeters of the longest side?

Answer 1

The side of the longest triangle would be 9cm.

Explanation:

First, we need to find x

To do this, we add all 3 sides together to get the perimeter (20) :

x + x + 3 + x + 5 = 20

3x + 8 = 20

We then use this equation to find x :

3x + 8 = 20

(minus 8 on both sides)

3x = 12

(divide by 3 on both sides)

x = 4

Now we have x, we substitute it into the longest side (x + 5)

4 + 5 = 9cm.