Triangle Area Calculator
Triangle area = base × perpendicular height / 2.
Open toolTriangle Angle Calculator
Find the third interior angle of a plane triangle. Both angles must be positive and their sum must be below 180°.
Free to useNo sign-upRuns in your browser
Enter your details
Enter the inputs, then select Calculate result.
Your result
Enter your details
Result will appear here
How Triangle Angle Calculator works
Find the third interior angle of a plane triangle.
Both angles must be positive and their sum must be below 180°. Applies to Euclidean plane triangles. Finite real numbers only. Display uses up to 12 significant digits; binary floating-point arithmetic can introduce rounding.
How to use Triangle Angle Calculator
Follow the labelled inputs.
Enter first angle in degrees
Replace the example with first angle in degrees. The field labels specify the expected format and units.
Input and settings
Check the remaining inputs
Set second angle in degrees. Both angles must be positive and their sum must be below 180°.
Tool result
Run, review and save
Select Calculate result. Review the calculated result, then copy it or download the result text.
Review the details
Examples and uses for Triangle Angle Calculator
Check the supplied example
The starting example produces 75°. Find the third interior angle of a plane triangle.
Use your own inputs
Read the labels for first angle in degrees and second angle in degrees. Both angles must be positive and their sum must be below 180°.
Record a reviewed result
Copy the calculated result into your notes. Keep the formula and assumptions with it if someone else needs to reproduce the calculation.
How to read the result
Read the units and assumptions with the output.
Find the third interior angle of a plane triangle.
Both angles must be positive and their sum must be below 180°. Applies to Euclidean plane triangles. Finite real numbers only. Display uses up to 12 significant digits; binary floating-point arithmetic can introduce rounding.
Supported input and limits
Check the stated scope before you run it.
Both angles must be positive and their sum must be below 180°. Applies to Euclidean plane triangles. Finite real numbers only. Display uses up to 12 significant digits; binary floating-point arithmetic can introduce rounding.
The input stays in this browser. Copy result and Download save the same displayed text.
More free tools to try
Choose another tool for your next calculation, conversion, or text task.
Arc Length Calculator
Arc length = angle / 360 × 2 × π × radius.
Open tool
Arithmetic Sequence Calculator
Calculate the nth term and finite sum of an arithmetic sequence.
Open tool
Binomial Distribution Calculator
Calculate the probability of exactly k binomial successes.
Open tool
Circle Area Calculator
Area = π × radius².
Open toolTriangle Angle Calculator: common questions
Answers about using Triangle Angle Calculator and understanding its results.
Which inputs does this tool accept?
Both angles must be positive and their sum must be below 180°. Applies to Euclidean plane triangles. Finite real numbers only. Display uses up to 12 significant digits; binary floating-point arithmetic can introduce rounding.
Can I copy or download the result?
Yes. Copy result copies the displayed text, and Download saves the same result as a text file. Calculations run in your browser without an account.
Calculate result with your input
Check the calculated result, then copy or download it.