Right Triangle Calculator
Hypotenuse, area, and perimeter of a right triangle from its two legs.
Worth Knowing
A right triangle's defining 90° angle makes it the most tractable shape in geometry: the two legs are perpendicular, so the area is simply half their product, and the hypotenuse follows from the Pythagorean theorem. This combination is why right triangles underpin trigonometry, navigation, and construction. The longest side is always the hypotenuse opposite the right angle, and it's always shorter than the two legs added together but longer than either one alone.
How to Use
- Enter Leg a into the first field of the Right Triangle Calculator.
- Fill in the rest: Leg b.
- Your result appears instantly as you type — there's no submit button or page reload.