I realize that many students cannot recall the number of size of the various Polygons. If you do not know the number of sides , you will not be able to solve Elementary Math Problems involving Polygons as you will not know what n value (i.e. no. of sides) to insert into the formulas. This Short Math Video show you how to memorize the number of sides of a Pentagon, Hexagon, Heptagon, Octagon, Nonagon and Decagon.