Ziquan makes a drawing in plane for art class, finite number of line segments
Source: Canadian Junior Mathematical Olympiad - CJMO 2020 p2
July 15, 2020
combinatoricssegments
Problem Statement
Ziquan makes a drawing in the plane for art class. He starts by placing his pen at the origin, and draws a series of line segments, such that the line segment has length . He is not allowed to lift his pen, so that the end of the segment is the start of the segment. Line segments drawn are allowed to intersect and even overlap previously drawn segments.
After drawing a finite number of line segments, Ziquan stops and hands in his drawing to his art teacher. He passes the course if the drawing he hands in is an by square, for some positive integer , and he fails the course otherwise. Is it possible for Ziquan to pass the course?