About this tool
Solve a right triangle with the Pythagorean theorem, or any triangle from three known values.
Right triangles use a² + b² = c² and sin A = a ÷ c. Other triangles use the law of cosines (c² = a² + b² − 2ab·cos C) and the law of sines (a ÷ sin A = b ÷ sin B). Area comes from Heron’s formula.
Formula: a² + b² = c² · c² = a² + b² − 2ab·cos C
Example: Triangle type = Right triangle (enter two sides), Side a = 3, Side b = 4, Side c (hypotenuse if right) = 0 → Side a = 3, Side b = 4.
Angles are in degrees. With two sides and an angle that is not between them (SSA), two triangles can exist; the first solution is shown.
Quick steps
- Enter your values — every field shows its unit.
- Press Calculate (or Try an example to see how it works).
- Read the results and copy them if you need them elsewhere.
The calculation runs in your browser. Nothing you type is sent to 1CLIK.
FAQ
How does the Triangle Calculator (Right Triangle & Hypotenuse) work?
Right triangles use a² + b² = c² and sin A = a ÷ c. Other triangles use the law of cosines (c² = a² + b² − 2ab·cos C) and the law of sines (a ÷ sin A = b ÷ sin B). Area comes from Heron’s formula.
What should I keep in mind?
Angles are in degrees. With two sides and an angle that is not between them (SSA), two triangles can exist; the first solution is shown.
Is my data sent anywhere?
No. The numbers stay on your device; the page only shows the result.