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Triangle Calculator
Solve any triangle from three sides or two sides and the angle between them: angles, area, perimeter and type.
Hypotenuse Calculator
Find the hypotenuse of a right triangle from its two legs with the Pythagorean theorem, plus angles and area.
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How to use this calculator
Enter your values. The result updates as you type; press Calculate to confirm and jump to the result on mobile. Use Share to send the calculator with your result.
Pythagorean theorem
c² = a² + b² → c = √(a² + b²)
It works only for right triangles (one 90° angle); c is the side opposite the right angle. Example: legs 3 and 4 → c = √25 = 5. Common whole-number triples: 3-4-5, 5-12-13, 8-15-17, 7-24-25.
For any triangle, use the Triangle Calculator.
Frequently asked questions
How do I find a leg if I know the hypotenuse?
a = √(c² − b²).
About this tool
- Written by
- [Author: to be assigned]
- Reviewed by
- Formula tests passed · human review pending
- Last updated
- 31 Oct 2026
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