Geometry & Trigonometry
Basic

Perimeter of a Triangle

Sum of the three sides of a triangle.

Formula

P=a+b+cP = a + b + c

Variables

a, b, cSide lengths

Example

A triangle with sides 3, 4, 5 has perimeter 3+4+5 = 12.

Did You Know?

The triangle inequality guarantees any two sides must together exceed the third — or the triangle can't close.

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