Pythagorean Theorem Calculator
Enter any 2 sides and leave 1 blank. Use c as the hypotenuse.
Formula: a² + b² = c²
Leave blank to solve for a.
Leave blank to solve for b.
Leave blank to solve for c.
Solved Side
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Area
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Perimeter
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Summary:
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Use this Pythagorean Theorem Calculator to find a missing side of a right triangle from the other two sides. It also calculates the triangle’s area and perimeter.
Calculation Method
The Pythagorean theorem is:
a² + b² = c²
Where a and b are the legs and c is the hypotenuse.
To find the hypotenuse:
c = √(a² + b²)
To find a missing leg:
a = √(c² − b²)
b = √(c² − a²)
Example
For a right triangle with legs of 6 and 8:
c = √(6² + 8²)
c = √(36 + 64) = √100 = 10
The hypotenuse is 10.
Important Note
The Pythagorean theorem applies only to right triangles. The hypotenuse is always the side opposite the 90° angle and must be the longest side.