Calculate the total length of the boundary of any triangle.
Side Lengths
Triangle Stats
Total Perimeter12
Semi-perimeter (s)6
About this calculator
What is Triangle Perimeter?
The perimeter of a triangle is the sum of the lengths of its three sides. It is a fundamental property used in various geometric calculations, including Heron's formula for area.
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Pro Tips
The sum of any two sides must be greater than the third side (Triangle Inequality Theorem).
For an equilateral triangle, P = 3a.
For an isosceles triangle, P = 2a + b.
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Fun Facts
"The perimeter of a triangle is the simplest one-dimensional measure of its size."
