A familiar situation
Find a rectangular room’s diagonal from its length and width.
How to use this calculator
- Enter known sides, first side, second side.
- Select Calculate to see the answer and its breakdown.
- Keep a scenario, change an input and compare the results.
Use consistent units and check the assumptions below before applying the result.
How pythagorean theorem is calculated
For legs a and b, c=√(a²+b²). If hypotenuse c and leg a are known, the remaining leg is √(c²−a²), requiring c>a. The hypotenuse is opposite the right angle and is always the longest side; checking this ordering prevents taking the square root of a negative value. Legs 3 and 4 yield hypotenuse √(9+16)=5.
a²+b²=c² for a right triangle.Legs 3 and 4 yield hypotenuse √(9+16)=5.
Assumptions & useful context
The result depends on the values you enter and the method described above. Displayed numbers may be rounded; calculations use the unrounded values. Check that this model matches your situation before relying on it.
Frequently asked questions
Can the hypotenuse be shorter than a leg?
No; it is the longest side of a right triangle.
Are inputs side lengths or coordinates?
Enter positive side lengths; coordinate geometry uses the distance calculator.