Shakhar Smorodinsky Ben-Gurion University of the Negev Mathematics We introduce several topics in plane combinatorial geometry such as point lines incidences, repeated distances, distinct distances, k-sets, sum-products etc. We also introduce some of the elementary combinatorial tools that were previously used to tackle these problems. Among them, the crossing-lemma which was applied to several of these problems by Laszlo Szekely in a seminal paper from 1997.