# How do you calculate the perimeter of an equilateral triangle?

Nov 20, 2015

The side length of the triangle multiplied by $3$.

#### Explanation:

The perimeter of any polygon is the sum of its side lengths. In an equilateral triangle, all of the sides are congruent (they are the same length).

Thus, if an equilateral triangle has a side length of $2$, the perimeter is $2 + 2 + 2$ because all of its sides are $2$.

We can generalize this rule by saying that if an equilateral has side length $s$, its perimeter is $s + s + s$, which is equivalent to $3 s$, or, the side length of the triangle multiplied by $3$.