Question 49
Given a set $\mathcal{L}$ of lines in general position in the plane (no two lines in $\mathcal{L}$ are parallel and no three lines are concurrent) and another line $\ell$, show that the total number of edges of all faces in the corresponding arrangement intersected by $\ell$ is at most $6|\mathcal{L}|$.
Chazelle et al., Edelsbrunner et al.
Chazelle et al., Edelsbrunner et al.