Mathematics Problem Archive

Graham: For every non-equilateral triangle T, show that it is possible to color the plane with three colors so that there is no monochromatic (congrue...

Straus: Is every polygonal room in the plane illuminable from some point? See this....

/Clark : What is the (homogeneous adjacency) spectrum of the Fano plane?...

Do there exist seven planar points in general position—no three collinear and no four concyclic—such that every pairwise distance is an integer?...