Euclid Book 1 - Proposition 47
Pythagoras' theorem

Index --- introduction --- definitions --- axioms and postulates --- propositions --- other

To be proved: In right-angled triangles the square on the side opposite the right angle equals the sum of the squares on the sides containing the right angle.

Step through proof by clicking on Next line:

There is a triangle ABC with angle BAC = 90°

Previous proposition - Next proposition

© Jo Edkins 2011 - Return to Euclid index