Presentation is loading. Please wait.

Presentation is loading. Please wait.

Find the polygon… Click on the polygon. Sorry… Polygons are closed shapes. They cannot have openings.

Similar presentations


Presentation on theme: "Find the polygon… Click on the polygon. Sorry… Polygons are closed shapes. They cannot have openings."— Presentation transcript:

1

2 Find the polygon… Click on the polygon.

3 Sorry… Polygons are closed shapes. They cannot have openings.

4 Polygons only have straight sides. They cant have curves. Sorry…

5 Congratulations! Polygons are closed shapes with straight sides. All triangles are polygons.

6 Find the polygon…

7 Sorry… Polygons only have straight sides.

8 Sorry… Polygons only have straight sides.

9 Excellent! All rectangles are polygons.

10 Find the polygon…

11 Sorry… Polygons are closed figures. They do not have holes.

12 Sorry… Polygons sides do not cross each other

13 All right!

14 (1-6) Angles of Polygons The word polygon is a Greek word. Poly gon Poly means many and gon means angle.

15 Definition of polygon A closed object Made up of straight line segments that do not cross each other Vertex Side

16 Names of some polygons Triangle Quadrilateral Pentagon Hexagon Heptagon Octagon Nonagon Decagon n-gon 3-sides 4-sides 5-sides 6-sides 7-sides 8-sides 9-sides 10-sides n -sides

17 What is the name of this polygon? 1.hexagon 2.octagon 3.pentagon a

18 How about this one? 1.octagon 2.hexagon 3.pentagon a

19 What is the name of this polygon?... 1.Quadrilateral 2.Pentagon 3.Triangle a

20 A polygon with six sides is called a hexagon. 1.True 2.False

21 A polygon with 5 vertices is called a quadrilateral. 1.True 2.False a

22 An octagon always has 8 equal sides. 1.True 2.False a

23 Congratulations!

24 A polygon with no side points inwards when extended Convex Polygons Concave Polygons A polygon with at least one side points inwards when extended. (Think: concave has a "cave" in it)

25 Regular Polygons A polygon is regular when all the angles are equal and all of the sides are congruent

26 Diagonals of Polygons Diagonal A line segment that connects two non consecutive vertices of a polygon.

27 180 o 6 sides 180 o 4 x 180 o = 720 o o Interior angles of Polygons 4 sides 2 x 180 o = 360 o 2 5 sides 3 x 180 o = 540 o 3 7 sides 5 x 180 o = 900 o 5

28 An exterior angle of a regular polygon is formed by extending one side of the polygon. Angle 1 is an exterior angle to angle 2 Exterior Angle + Interior Angle =180 o 1 Exterior angles of Polygons 2

29

30 120 0

31

32 360 0

33 60 0

34

35

36

37

38 90 0

39

40

41

42 Sum of exterior angles = 360º Sum of Interior Angles = (n – 2) 180 # of sides Regular polygons Measure of each exterior angle of a regular polygon = # of sides of a regular polygon = # of sides exterior angle + interior angle = 180º

43 Find the measure of each interior angle of a regular nonagon Example1: Step 1: Nonagon has 9 sides so n=9 Step 3: measure of interior angle = Step 2: measure of each ext. angle =

44 Find the measure of each exterior angle of a regular decagon. Example2: Step 1: Decagon has 10 sides so n=10 Step 2: measure of each ext. angle =

45 How many sides are there in a regular polygon if each interior angle measures 165 o ? Example3: Step 2: # of sides of a regular polygon = Step 1: measure of exterior angle =

46 Is it possible to have a regular polygon with an exterior angle equal to 40 o ? If yes find the number of sides Example4: Step 2: # of sides = Step 1: yes

47 Homework (12 – 30) even pages 407, 408


Download ppt "Find the polygon… Click on the polygon. Sorry… Polygons are closed shapes. They cannot have openings."

Similar presentations


Ads by Google