Pythagorean Theorem Calculator
Find the missing side of a right triangle using a² + b² = c². Enter any two sides and leave the unknown side blank.
Enter any two sides of a right triangle and leave the unknown side blank. The calculator will solve for the missing side using a² + b² = c².
About this Calculator
Find the missing side of a right triangle using a² + b² = c². Enter any two sides and leave the unknown side blank.
Formula & Calculations
Formula
a² + b² = c²Where:
- a=Leg 1 of the right triangle
- b=Leg 2 of the right triangle
- c=Hypotenuse (longest side)
Assumptions
- The triangle must be a right triangle (one angle equals exactly 90°).
- Side c is always the hypotenuse, the side opposite the right angle.
- Side c must be the longest side; ensure a and b are the legs.
Calculation Examples
Example 1
Inputs:a = 3, b = 4, c = (blank)
Result:c = 5
√(3² + 4²) = √(9 + 16) = √25 = 5.
Example 2
Inputs:a = 5, b = (blank), c = 13
Result:b = 12
√(13² − 5²) = √(169 − 25) = √144 = 12.
Frequently Asked Questions
Does this calculator only work for right triangles?
Yes, the Pythagorean Theorem applies exclusively to right triangles where one angle is exactly 90 degrees.
How do I know which side is the hypotenuse?
The hypotenuse is always the longest side of a right triangle and is opposite the right angle. In the formula, it is represented by c.