Cue sports tables are usually heated to stave off moisture and provide a consistent playing surface. The length of the pool table will typically be a function of space, with many homeowners purchasing an table as a compromise. Full-size pool tables are 4.5 by (interior dimensions). High-quality tables have a made of thick slate, in three pieces to prevent warping and changes due to temperature and humidity. Smaller bar tables are most commonly made with a single piece of slate. Pocket billiards tables of all types normally have six pockets, three on each side (four corner pockets, and two side or middle
Outer billiard Tabachnikov showed that all orbits are unbounded for a certain class of convex polygons in the hyperbolic plane. The authors call such polygons "large". (See the reference for the definition.) Dogru and Otten then extended this work in 2011 by specifying the conditions under which a regular polygonal table in the hyperbolic plane have all orbits unbounded, that is, are large. In ordinary polygonal billiards, the existence of periodic orbits is a major unsolved problem. For instance, it is unknown if every triangular shaped table has a periodic billiard path. More progress has been made for outer billiards, though the