Right Triangle Calculator
c=√(a²+b²); angle A=arcsin(a/c); angle B=90°−Ac=5; A≈36.87°; B≈53.13°
Free online tool
Right Triangle Calculator
Enter the lengths of two sides to solve the complete right triangle.
Instant calculation
Right Triangle Calculator
Enter the lengths of two sides to solve the complete right triangle.
Your result
Calculation
Your numbers stay in this browser. Nothing is uploaded or saved.
Three clear steps
How to use this calculator
- 01
Enter side A
Type the first known side length.
- 02
Enter side B
Type the second known side length.
- 03
See complete triangle
Calculate to see all three sides and angles.
The formula
How this calculation works
Uses the Pythagorean theorem for the third side and inverse trig for angles.
Check the method
Worked examples
Each example follows the same formula used by the calculator.
Sides 3 and 4 — complete triangle?
c=5; A≈36.87°; B≈53.13°Sides: 3,4,5; Angles: 36.87°, 53.13°, 90°Common questions
Questions about this calculation
What is the Right Triangle Calculator?
The Right Triangle Calculator helps you calculate all sides and angles of a right triangle from two known sides. Enter your values and select Calculate to get an instant result.
How is the result calculated?
Uses the Pythagorean theorem for the third side and inverse trig for angles.
Can you show an example?
Example: Sides 3 and 4 — complete triangle? — Sides: 3,4,5; Angles: 36.87°, 53.13°, 90°.
Is my data saved when I use the Right Triangle Calculator?
No. All calculations run locally in your browser. Your inputs and results are never uploaded, stored or shared with anyone.
Is the Right Triangle Calculator free to use?
Yes. The Right Triangle Calculator is completely free. No account, sign-up or payment is required. It works on mobile, tablet and desktop.
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