This is a PowerPoint slide show that introduces and defines the following terms: polygons (regular and irregular), triangles, quadrilaterals, pentagons, hexagons, and octagons. It also differentiates between scalene, equilateral, isosceles, right, acute, and obtuse triangles. There is a diagram/flow chart showing the relationship between the different quadrilaterals. It's broken down into parallelograms and trapezoids, and the parallelograms side is broken down further into rectangle and rhombus, ending with a square (which fits both the rectangle and the rhombus description). You can use the slide show to teach a lesson, or you can make posters or handouts of the separate slides.