Pythagorean Theorem Calculator
Right triangle side from a²+b²=c².
Result
Missing side
5
Common questions
How do I use the Pythagorean theorem?
For a right triangle: a² + b² = c², where c is the hypotenuse. Enter any two sides and the calculator finds the third. For example, sides 3 and 4 give hypotenuse √(9+16) = 5.
Can I use the Pythagorean theorem for non-right triangles?
No, it only applies to right triangles. For other triangles, use the Law of Cosines: c² = a² + b² − 2ab·cos(C).