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# Naming angles-of-polygons

MATHEMATICS
Published on: Mar 3, 2016
Published in: Science
Source: www.slideshare.net

#### Transcripts - Naming angles-of-polygons

• 1. INNOVATIVE LESSON TEMPLATE
• 2. What ddooeess tthhee wwoorrdd ““ppoollyyggoonn”” mmeeaann?? WWhhaatt iiss tthhee ssmmaalllleesstt nnuummbbeerr ooff ssiiddeess aa ppoollyyggoonn ccaann hhaavvee?? WWhhaatt iiss tthhee llaarrggeesstt nnuummbbeerr ooff ssiiddeess aa ppoollyyggoonn ccaann hhaavvee??
• 3. Triangle Quadrilateral Pentagon Hexagon Heptagon Octagon Nonagon Decagon Dodecagon n-gon
• 4. Hip Bone’s connected to the… Classifying Polygons Polygons with 3 sides… Triangles Polygons with 4 sides… Quadrilaterals Polygons with 5 sides.. Pentagons But wait we have more polygons Polygons with 6 sides… Hexagons Polygons with 7 sides… Heptagons Polygons with 8 sides… Octagons But still we have more polygons Polygons with 9 sides… Nonagons Polygons with 10 sides… Decagons Polygons with 12 sides… Dodecagons And now we have our polygons
• 5. F Important Terms A B C E D A VERTEX is the point of intersection of two sides A segment whose endpoints are two nonconsecutive vertices is called a DIAGONAL. CONSECUTIVE VERTICES are two endpoints of any side. Sides that share a vertex are called CONSECUTIVE SIDES.
• 6. More Important Terms EQUILATERAL - All sides are congruent EQUIANGULAR - All angles are congruent REGULAR - All sides and angles are congruent
• 7. Polygons are named by listing its vertices consecutively. A B F C E D
• 8. # of sides # of triangles Sum of measures of interior angles 3 1 1(180) = 180 4 2 2(180) = 360 5 3 3(180) = 540 6 4 4(180) = 720 n n-2 (n-2) ·180
• 9. If a convex polygon has n sides, then the sum of the measure of the interior angles is (n – 2)(180°)
• 10. Ex. 1 Use the regular pentagon to answer the questions. A)Find the sum of the measures of the interior angles. 540° B)Find the measure of ONE interior angle 108°
• 11. Two more important terms Exterior Angles Interior Angles
• 12. If any convex polygon, the sum of the measures of the exterior angles, one at each vertex, is 360°. 1 2 3 4 5 mÐ1+mÐ2 +mÐ3+mÐ4 +mÐ5 = 360
• 13. If any convex polygon, the sum of the measures of the exterior angles, one at each vertex, is 360°. 1 3 2 mÐ1+mÐ2 +mÐ3 = 360
• 14. If any convex polygon, the sum of the measures of the exterior angles, one at each vertex, is 360°. 1 3 2 4 mÐ1+mÐ2 +mÐ3+mÐ4 = 360
• 15. Ex. 2 Find the measure of ONE exterior angle of a regular hexagon. sum of the exterior angles number of sides  = 60° = 360 6
• 16. Ex. 4 Each exterior angle of a polygon is 18°. How many sides does it have? exterior angle sum of the exterior angles = n = 20 number of sides 360  =18 n