Right Triangle Calculator

Enter exactly TWO known values to calculate the rest.
Angle C is always 90°.

Leg a

Leg b

Hypotenuse c

Angle A (°)

Angle B (°)

Calculated Missing Values

Leg a

Leg b

Hypotenuse c

Angle A

0°

Angle B

0°

Area

What is a Right Triangle?

A right triangle is a special type of triangle that has exactly one interior angle measuring 90 degrees (a "right angle"). This single property unlocks some of the most famous and useful mathematics in human history, including the Pythagorean Theorem and Trigonometry (SOH CAH TOA).

The Pythagorean Theorem

If you know the lengths of any two sides of a right triangle, you can always find the third side using the Pythagorean Theorem. The longest side, opposite the 90-degree angle, is always called the Hypotenuse (c). The other two sides are called the Legs (a and b).

a² + b² = c²

To find the hypotenuse: c = √(a² + b²)
To find a leg: a = √(c² - b²)

Using Trigonometry (SOH CAH TOA)

If you only know one side length and one angle, you can use basic sine, cosine, and tangent functions to find the rest of the shape. Our smart calculator automatically identifies what information you provided and applies the correct trigonometric formulas instantly.