This document introduces several basic polygons: triangles, which can be categorized by side lengths (scalene, isosceles, equilateral) or angles (acute, obtuse, right); parallelograms such as rectangles and rhombi; trapezoids; and polygons with 5 or more sides such as pentagons, hexagons, octagons, and decagons. It provides examples and definitions of different types of each polygon shape.

1. SHAPES!Introduction to some basic polygons

2. What do you know already?How many shapes can you think of off the top of your head?Where have you seen these shapes before?

3. What is a polygon?2 dimensional ClosedMade of straight linesWhich of these are polygons?NoYesNo

4. TriangleAny three sided polygonTypes of Triangles:AcuteObtuseRightScaleneIsoscelesEquilateralLets learn about the different kinds

5. Looking at side lengthsScalene IsoscelesTwo of the sides on the triangle are the same lengthAll three sides of the triangle are different lengthEquilateral All three sides of the triangle are equal

6. Looking at the anglesAcuteALL of the angles in the triangle is acute (less than 90°)ObtuseOne of the angles in the triangle is an obtuse angle (greater than 90°)RightThere is one right angle (90°) in the triangle

7. ParallelogramFour sided polygonOpposite sides are parallel

8. RectanglePolygon4 sides4 right angles (90°)Parallelogram

9. SquareSpecial type of rectangleFour EQAUL sidesFour 90° anglesParallelogram

10. RhombusAnother parallelogramOpposite sides are parallelFour EQUAL sidesWhich is a rhombus?

11. TrapezoidOnly one pair of opposite sides are parallelFour sidesPolygon, but NOT a parallelogram

12. PentagonPolygon5 sidedRegular Pentagon has 5 equal sidesWhich on is the regular pentagon and which is just a pentagon?

13. Hexagonhttp://minglearound.files.wordpress.com/2010/12/nuts-bolts-washers.jpgPolygon6 sidedRegular Hexagon has 6 sides of equal length

14. OctagonPolygonEight sidesRegular octagon has 8 sides of equal lengthPhoto taken by Jillian Carey

15. DecagonPolygonTen sided figureRegular decagon has ten equal sidesWhich one of these is the regular decagon?