Monochromatic triangle

A monochromatic triangle is a term commonly used in the context of combinatorics and Ramsey theory. It refers to a triangle formed by points that are all the same color within a given coloring of a set of points. For instance, if you have a set of points in a plane, you might color each point either red or blue. A monochromatic triangle would be a triangle whose vertices are all points of the same color, either all red or all blue.