Students will learn how to determine whether a polygon is convex, concave, regular, or irregular. Students can practice this skill here. You should also demonstrate to students that a polygon can be equilateral or equiangular without being regular. Additionally, show that concave polygons can be equilateral but not equiangular. They cannot be equiangular because all concave polygons have at least one angle greater than \(180^\circ\) and at least one angle less than \(180^\circ.\) Conclude by giving your students this challenge.