Perimeter of a Triangle Calculator

This Perimeter of a Triangle Calculator helps you find the total distance around a triangle when the lengths of all three sides are known. It uses the formula P = a + b + c, where a, b, and c are the side lengths, and the answer is written in units. Add the three side lengths together to get the perimeter. It is a simple way to check answers, understand the triangle perimeter formula, and practise basic geometry step by step.

In the diagram, the sides are labeled a, b, and c.

Step-by-step method

1. Identify what is given.
2. Write the formula.
3. Substitute the values and add the side lengths.

Formula:

Example 1: a = 3, b = 4, c = 5

Step 1 - Identify what is given.

In this problem: The given side lengths are a = 3, b = 4, and c = 5.

Step 2 - Write the formula.

In this problem: Use the triangle perimeter formula: P = a + b + c.

Step 3 - Substitute the values and add the side lengths.

In this problem: Substitute a = 3, b = 4, and c = 5: P = 3 + 4 + 5 = 12.

Final answer: P = 12

Example 2: a = 6.5, b = 2, c = 1.25

Step 1 - Identify what is given.

In this problem: The given side lengths are a = 6.5, b = 2, and c = 1.25.

Step 2 - Write the formula.

In this problem: Use the triangle perimeter formula: P = a + b + c.

Step 3 - Substitute the values and add the side lengths.

In this problem: Substitute a = 6.5, b = 2, and c = 1.25: P = 6.5 + 2 + 1.25 = 9.75.

Final answer: P = 9.75