It is known that we can't with just a straight edge, given a line and a point out of the line in a plane to construct other line, passing through the point, parallel to the first. I know a proof of this fact lying on projective geometry.
However, I also know that is actually possible, with just a straight edge, given two parallel lines and a point out of both in a plane, construct a parallel to both lines and passing through the point. But I can't find neither the algorithm nor the demonstration of it.
Someone know how to do?