Index --- introduction --- definitions --- axioms and postulates --- propositions --- other
To be proved: A straight line falling on parallel straight lines makes the alternate angles equal to one another, the exterior angle equal to the interior and opposite angle, and the sum of the interior angles on the same side equal to two right angles.
Step through proof by clicking on Next line:
Previous proposition - Next proposition
© Jo Edkins 2010 - Return to Euclid index