# Perimeter of an Isosceles Triangle     (No Ratings Yet) Loading... The perimeter of an isosceles triangle is obtained as the addition of the three sides of the triangle. Having two equal sides, the perimeter is twice the repeated side (a) plus the different side (b). In an isosceles triangle, if the repeating side (a) and the angle they form are known, the other side (b) should be found by Law of Cosines (Cosine Rule). Download this calculator to get the results of the formulas on this page. Choose the initial data and enter it in the upper left box. For results, press ENTER.

Note. Courtesy of the author: José María Pareja Marcano. Chemist. Seville, Spain.

## Exercise Being an isosceles triangle with two equal sides, a=3 cm and a different side of b=2 cm.

What is its perimeter?

To calculate this perimeter we add the repeated side multiplied by two plus the unequal side, i.e.: It is obtained that the isosceles triangle’s perimeter is 8 cm.

AUTHOR: Bernat Requena Serra

YEAR: 2018

### 3 Responses

1. Barton Frutiger says:

as soon as I detected this web site I went on reddit to share some of the love with them.

2. Aformations says:

A common error is to assume that a triangle that has a fixed perimeter must also have a fixed area. This is definitely

• lol says:

Right