2014 Guts #15: Pivot Lines in a Pentagon
Source:
April 20, 2014
geometry
Problem Statement
Given a regular pentagon of area , a pivot line is a line not passing through any of the pentagon's vertices such that there are vertices of the pentagon on one side of the line and on the other. A pivot point is a point inside the pentagon with only finitely many non-pivot lines passing through it. Find the area of the region of pivot points.