If there are two parallel straight lines, and random points are taken on each of them, then the straight line joining the two points is in the same plane as the parallel (straight lines). * Let $AB$ and $CD$ be two parallel straight lines, and let the random points $E$ and $F$ have been taken on each of them (respectively). * I say that the straight line joining points $E$ and $F$ is in the same (reference) plane as the parallel (straight lines).
(not yet contributed)
Proofs: 1