How to calculate the perimeter of a triangle

The perimeter of any geometric figure corresponds to the sum of the length of all its sides and for this there are mathematical formulas that help us find it. In the case of triangles, it should be noted that the calculation will vary depending on the type of triangle and in this article we explain in detail how to calculate the perimeter of a triangle, whether it is equilateral, isosceles or scalene.

Calculate the perimeter of an equilateral triangle

Equilateral triangles are those whose three sides have the same length and, therefore, their angles also measure the same. So, to obtain the perimeter of an equilateral triangle, you must multiply by three the value of the length of its side:

P = 3 xl

Let's take an example to see it clearer: calculate the perimeter of an equilateral triangle of 6 cm on each side.

P = 3 x 6 = 18 cm

Calculate the perimeter of an isosceles triangle

On the other hand, isoscele triangles are those in which two of its sides are equal and one different, which will be the base. So, in this case, to find the perimeter of the triangle you must apply the formula that says you must multiply the value of the side by two and add the length of the base:

P = 2 xl + b

Example: Calculate the perimeter of an isosceles triangle whose equal sides measure 8 cm and the base 3 cm.

P = 2 x 8 + 3 = 16 + 3 = 19 cm

Calculate the perimeter of a scalene triangle

Finally, the last type of triangles is the scalene, in which each of the sides has a different size. So, in this case, you must limit yourself to adding the value of the three lengths to obtain the perimeter:

P = a + b + c

Suppose that the values of the sides of a scalene triangle are 5 cm, 8 cm and 10 cm, calculates its perimeter.

P = 5 + 8 + 10 = 23 cm