Pythagorean Theorem Calculator
Find the missing side of a right triangle from the other two, with the exact answer as a surd (such as 2√5) and the angles, area and perimeter.
Change the values and press Calculate to work out your own figures.
Enter any two of the three sides; surds such as 2√5 are allowed.
Show the working
- b = √(c² − a²)
- b = √16 = 4
How to use it
Enter any two of the three sides; surds such as 2√5 are allowed.
Enter the values you know (decimals, fractions, surds such as 2√5, or angles such as π/3 in radians). Show the working gives the rule used at each step.
Key facts
a² + b² = c²
Exact answers
When the sides are whole numbers, fractions or surds, the missing side is shown as a simplified surd: legs 1 and 1 give √2.
Questions
What is the hypotenuse of a 3-4 right triangle?
5.
Does it work for any triangle?
Only right triangles; use the law of cosines otherwise.
Formulas
a² + b² = c²
Sources
Limitations
- Angles can be typed in degrees or radians; radians may be written with π (π/3, 2pi/3).