1. THE WORLD OF POLYGONS
LESSON 4

2. ACTIVITY:BIRDSEYE VIEW

3. ACTIVITY:BIRDSEYE VIEW

4. ACTIVITY:BIRDSEYE VIEW

5. ACTIVITY:BIRDSEYE VIEW
IS SHAPE 1 A POLYGON?

6. ACTIVITY:BIRDSEYE VIEW
IS SHAPE 2 A POLYGON?

7. ACTIVITY:BIRDSEYE VIEW
IS SHAPE 3 A POLYGON?

8. DEFINITION
Polygon, in geometry, a simple closed two-dimensional figure formed by the joining of three or more straight line segments, called SIDES.

9. DEFINITION
A figure is simple if it extends in no more than two directions from any point and closed if its starting point is the same as its endpoint.

10. DEFINITION
These restrictions require that the sides of a polygon not cross each other and that pairs of sides intersect at their ENDPOINTS, which are called VERTICES.

11. POLYGONS ARE NAMED AND CLASSIFIED ACCORDING TO THEIR NUMBER OF SIDES.

12. EXAMPLES
TRIANGLE
RECTANGLE
PENTAGON

13. EXAMPLES
HEXAGON

14. REGULAR POLYGONS 6 SIDES 3 SIDES 4 SIDES 5 SIDES 7 SIDES 8 SIDES

15. REGULAR POLYGONS
ALL ANGLES ARE EQUAL and ALL SIDES ARE EQUAL.

16. All polygons have an equal number of sides and vertices.
REMEMBER
All polygons have an equal number of sides and vertices.

17. EXAMPLE
TRIANGLE
3 SIDES.
3 VERTICES
3 ANGLES

18. Polygons are also classified as CONVEX and NONCONVEX.

19. Polygons are also classified as CONVEX and NONCONVEX.

20. What is the difference between CONVEX and NONCONVEX POLYGONS?

21. A POLYGON IS CONVEX IF A SEGMENT JOINING ANY 2 POINTS OF THE POLYGON LIES COMPLETELY INSIDE THE POLYGON.
CONVEX

22. OTHERWISE THE POLYGON IS NONCONVEX .

23. EXERCISES
TELL WHETHER OR NOT EACH OF THE FOLLOWING IS A POLYGON.

24. QUIZ
TELL WHETHER A POLYGON IS CONVEX OR NOT.

25. POLYGONS
LESSON 5

26. All polygons have an equal number of sides and vertices.
RECALL
All polygons have an equal number of sides and vertices.

27. TRIANGLE
QUADRILATERAL
PENTAGON
HEXAGON
HEPTAGON
OCTAGON
NONAGON
DECAGON

28. POLYGON PARTS

29. Side - one of the line segments that make up the polygon.
POLYGON PARTS
Vertex - point where two sides meet. Two or more of these points are called vertices.
Side - one of the line segments that make up the polygon.

30. Diagonal - a line connecting two vertices that isn't a side.
POLYGON PARTS
Diagonal - a line connecting two vertices that isn't a side.

31. POLYGON PARTS
Exterior Angle - Angle formed by two adjacent sides outside the polygon.
Interior Angle - Angle formed by two adjacent sides inside the polygon.

32. TRIANGLE