Hungary-Israel Binational 1999\2
Source: Maximal number of acute triangles
October 30, 2008
analytic geometrygraphing linesslopecombinatorics unsolvedcombinatorics
Problem Statement
2n\plus{}1 lines are drawn in the plane, in such a way that every 3 lines define a triangle with no right angles. What is the maximal possible number of acute triangles that can be made in this way?