Julián chooses 2007 points of the plane between which there are no 3 aligned, and draw with red all the segments that join two of those points. Next, Roberto draws several lines. Its objective is for each red segment to be cut inside by (at least) one of the lines. Determine the minor ℓ lines such that, no matter how Julián chooses the 2007 points, with the properly chosen ℓ lines, Roberto will achieve his objective with certainty. combinatoricsgeometrycombinatorial geometry