Triangle Type Classifier

Classify a triangle by side lengths (scalene, isosceles, equilateral) and angles (acute, right, obtuse).

Formula

If a²+b²=c² → Right; a²+b²>c² → Acute; a²+b²

Sides: equilateral (all equal), isosceles (two equal), scalene (all different). Angles: determined by comparing a²+b² to c².

Examples

3-4-5 (right)

5-5-5 (equilateral)

5-5-8 (isosceles obtuse)

Frequently Asked Questions

What is a scalene triangle?

A triangle with all three sides of different lengths.

How do I check if a triangle is obtuse?

If the square of the longest side is greater than the sum of squares of the other two sides.

About this Calculator

Classify a triangle by side lengths (scalene, isosceles, equilateral) and angles (acute, right, obtuse). All calculations are performed in your browser for instant results. Formulas are mathematically exact using JavaScript's built-in Math functions.