Paritian

Mathematics

Pythagorean Theorem Calculator

Find the hypotenuse of a right triangle from the two shorter sides.

Results

Hypotenuse 5 m
Angle 53.130 °
The shape, to scale
Pythagorean Theorem CalculatorPythagorean Theorem Calculator: a = 3.00 m, b = 4.00 m, 36.87°, 53.13°, c = 5.00 ma = 3.00 mb = 4.00 mc = 5.00 m53.13°36.87°

What this tool does

The oldest useful formula in the collection, and still the fastest way to find a diagonal, check that a corner is square or work out a cable run across a room. The angle between the hypotenuse and side a is shown as well.

Formula

c = √(a² + b²)

Variables

SymbolMeaningUnit
aSide am
bSide bm
cHypotenusem
angAngle°

Worked example

  • Side a3 m
  • Side b4 m
  • Hypotenuse5 m
  • Angle53.130 °

Limitations

  • Mixing units is the most common source of error. Convert every input to the units shown next to each field before calculating.

Frequently asked questions

How do builders use this to square a corner?

With the 3-4-5 method. Measure 3 units along one wall and 4 along the other; if the corner is a true right angle, the distance between those two marks is exactly 5. Any multiple works — 30 cm, 40 cm, 50 cm, or 3 m, 4 m, 5 m for a larger and more accurate check.