Rewrite this using modern terminology and notation. Criticize the statement or it's proof if you can.

Euclid's Proposition 7

Given two straight lines constructed from the ends of a straight line and meeting in a point, there cannot be constructed from the ends of the same straight line, and on the same side of it, two other straight lines meeting in another point and equal to the former two respectively, namely each equal to that from the same end.

maybe not that easy to reword...help me out.