Triangle Angle Calculator

Calculate the missing angles and sides of any triangle by entering the known values. Perfect for geometry, trigonometry, and practical measurements.

Triangle Calculator

Angle A (°)

Side a

Angle B (°)

Side b

Angle C (°)

Side c

Enter any 3 values (including at least one side) to calculate the rest. Or enter 2 angles to get the 3rd.

How it works

The sum of all interior angles in any flat triangle is always 180 degrees (or π radians). If you know two angles, you can easily find the third by subtracting their sum from 180.

Law of Cosines and Sines

For more complex scenarios where you only know the lengths of the sides (SSS) or a combination of sides and angles (SAS, ASA, AAS), we apply the Law of Cosines and the Law of Sines to determine the exact properties of your triangle.