Triangle Angle Calculator

Triangle Angle Calculator

Find the third angle of a triangle from the other two angles.

Last updated: June 2026 | By Patchworkr Team

Interior Angle Solver
Result
Enter two valid angles to compute the third.

Formula

C = 180 - A - B

How to Use It

  1. Enter two positive angles less than 180 degrees.
  2. Make sure their sum is less than 180 degrees.
  3. Read the third angle from the result panel.

Worked Example

If A = 65 degrees and B = 52 degrees, then C = 180 - 65 - 52 = 63 degrees.

The three angles sum to 180 degrees, which is the defining fact used here.

Notes

The calculator rejects impossible inputs where the first two angles already use up 180 degrees or more.

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