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Pythagorean Theorem Calculator

Calculate the hypotenuse or a missing leg of a right triangle using a² + b² = c².

FREE 2 MODES

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📐 The Pythagorean Theorem

The Formula
a² + b² = c²
Find Hypotenuse
c = √(a² + b²)
Find a Leg
a = √(c² - b²)

💡 Examples

Classic 3-4-5 triangle

a = 3, b = 4

c = √(9 + 16) = √25 = 5

Ladder against a wall — ladder = 10 ft, base = 6 ft

Find height: a = 6, c = 10

b = √(100 - 36) = √64 = 8 ft

💡 Fun Fact

The 3-4-5 right triangle has been known since ancient Egypt. Builders used knotted ropes with these proportions to create perfect right angles.

Common Right Triangles

3, 4c = 5
5, 12c = 13
8, 15c = 17
7, 24c = 25