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Pythagorean theorem
a² + b² = c² in a right triangle, and where it comes from.
In a right triangle the square built on the hypotenuse has the same area as the two squares on the legs put together. That single fact gives the distance formula, the equation of a circle, and half of trigonometry.
Worked example: hypotenuse of 3 and 4
Step by step
- c^2 = a^2 + b^2 = 3^2 + 4^2 = 25
Pythagoras: in a right triangle the square on the hypotenuse equals the sum of the squares on the legs.
- c = \sqrt{25} = 5
Take the square root.
Reveal the answer
c = 5