Cubic graphs have bounded slope parameter

We show that every nite connected graph G with maximum degree three and with at least one vertex of degree smaller than three has a straight-line drawing in the plane satisfying the following conditions. No three vertices are collinear, and a pair of vertices form an edge in G if and only if the segment connecting them is parallel to one of the sides of a previously xed regular pentagon. It is also proved that every nite graph with maximum degree three permits a straight-line drawing with the above properties using only at most seven dierent edge slopes.