Transcript Document
Polygons Grade 6 Geometry What is a Polygon???? . A polygon is a closed plane figure with 3 or more sides, it must have all straight lines, no curves Look around the room, with a partner, make a list of polygons in the classroom. Classifying Polygons by # of Sides 3 sided Polygon = Triangle Hint: Think “Tri”cycle, “tri”pod, “Tri”lateration (Tri means 3) Classifying Polygons by # of Sides 4 sided Polygon = Quadrilateral Hint: Think “Quad”rant, “Quad”ruple, “Quad” (AKA 4-Wheeler) Classifying Polygons by # of Sides 5 sided Polygon = Pentagon Hint: Think “Pent”athalon, or the government building “The Pentagon” Classifying Polygons by # of Sides 6 sided Polygon = Hexagon Hint: Both “Hexagon” and “Six” have an ‘x’ in them Classifying Polygons by # of Sides 7 sided Polygon = Heptagon Can you come up with a hint for remember a heptagon? Classifying Polygons by # of Sides 8 sided Polygon = Octagon Hint: “oct”opus – 8 legs Classifying Polygons by # of Sides 9 sided Polygon = Nonagon Hint: “Non” is similar to “Nine” Classifying Polygons by # of Sides 10 sided Polygon = Decagon Hint: Think “Dec”ade (10 years Classifying Polygons by # of Sides # of Sides Name 3 Triangle 4 Quadrilateral 5 Pentagon 6 Hexagon 7 Heptagon 8 Octagon 9 Nonagon 10 Decagon Two Types of Polygons Convex – all vertices point outward Concave – at least one vertex points inward towards the center of the polygon (The side looks like it “caved” in) Regular Polygons A Regular Polygon is a polygon in which all sides are the same length. Equilateral Triangle Square Review of Similar Triangles • 2 Triangles are similar if they have the same shape (i.e. the same angle in the same positions) Similar Polygons The same is true of polygons. 2 polygons are similar if they have the same angles in the same positions (i.e. same shape) Similar Trapezoids ^ Similar Pentagons ^ Similar Rectangles Parallel Sides… Reflex Angle … Parallel Sides: Two lines on a plane that never meet. They are always the same distance apart. Reflex Angle: An angle that is greater than 180 degrees On chart paper, draw a large Venn diagram with loops. Decide how you will label each loop. Choose from these attributes: Regular Quadrilateral Parallel Sides Irregular Pentagon Equal Sides Triangle Hexagon Reflex Angle Acute Angle Right Angle Obtuse Angle Using the shapes provided, trace them into their appropriate categories