About this Right Triangle
A right triangle has one 90-degree angle. This simple property allows us to use the Pythagorean Theorem and Trigonometry to solve for unknown sides and angles.
Who this calculator is for
- Students solving Pythagorean theorem and basic trigonometry problems.
- Builders and DIYers checking square corners or diagonal measurements.
- Anyone converting two perpendicular side lengths into a hypotenuse, area, and acute angles.
When to use it
- Use this calculator when you know the two legs of a right triangle and need the remaining measurements.
- Use it to check ladder, ramp, framing, or coordinate-geometry problems.
- Use it before moving into distance, triangle, area, or slope calculations.
How to use this calculator
- Enter the length of Side A (Leg 1).
- Enter the length of Side B (Leg 2).
- The calculator solves for the Hypotenuse (C), Area, and Angles.
Key assumptions
- Both inputs are the perpendicular legs of a right triangle, not a leg and hypotenuse.
- Leg lengths are treated as positive measurements in the same unit.
- Angles are reported in degrees and rounded for display.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
Pythagorean Theorem: a² + b² = c².
Area: (a × b) / 2.
Angles: Calculated using inverse tangent (arctan).
Inputs explained
Legs (a, b)
The two sides that meet at the right angle.
Hypotenuse (c)
The longest side, opposite the right angle.
Understanding your results
The angles will always sum to 180° (90° + Angle A + Angle B).
Example scenarios
3-4-5 Triangle
Side A=3, Side B=4. Result: Hypotenuse=5. Area=6.
Key Features
- Instant Calculation
- Private & Secure
- Mobile Optimized
Glossary of Terms
- Hypotenuse
- The longest side of a right triangle.
- Theta (θ)
- A symbol used to represent an unknown angle.