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Right Triangle Calculator

Find the hypotenuse, area, perimeter and angles of a right triangle.

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Understanding your result

This assumes a right angle between sides a and b.

Formula and method

Hypotenuse c = √(a² + b²); area = ½ × a × b; angles come from the arctangent of the opposite over adjacent sides.

Worked example

Legs of 3 and 4 give a hypotenuse of 5 and an area of 6.

How to use this tool

  1. Enter side a and side b (the legs).
  2. Press Calculate.

Common mistakes to avoid

  • Entering the hypotenuse as one of the legs.

About the Right Triangle Calculator

Enter the two legs of a right triangle to find the hypotenuse, area, perimeter and the two acute angles.

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Frequently asked questions

What is the Pythagorean theorem?

In a right triangle, the square of the hypotenuse equals the sum of the squares of the other two sides.