POLYGONS – Introduction

1. POLYGONS – Introduction A polygon is closed plane figure with three or more sides. A stop sign is an example of a polygon. It has vertices and no segments intersect. STOP

2. POLYGONS – Introduction A polygon is closed plane figure with three or more sides. A stop sign is an example of a polygon. It has vertices and no segments intersect. All segments of the polygon must intersect with two other segments at their endpoints. These are all polygons

3. POLYGONS – Introduction A polygon is closed plane figure with three or more sides. A stop sign is an example of a polygon. It has vertices and no segments intersect. All segments of the polygon must intersect with two other segments at their endpoints. Lastly , they enclose space in a plane. These are all polygons

4. POLYGONS – Introduction A polygon is closed plane figure with three or more sides. A stop sign is an example of a polygon. It has vertices and no segments intersect. All segments of the polygon must intersect with two other segments at their endpoints. Lastly , they enclose space in a plane. There are points on, inside, and outside each polygon.

5. POLYGONS – Introduction A polygon is closed plane figure with three or more sides. A stop sign is an example of a polygon. It has vertices and no segments intersect. All segments of the polygon must intersect with two other segments at their endpoints. Lastly , they enclose space in a plane. These figures ARE NOT polygons. Does not close space and does not have segments joined with the endpoints of two other segments.

6. POLYGONS – Introduction A polygon is closed plane figure with three or more sides. A stop sign is an example of a polygon. It has vertices and no segments intersect. All segments of the polygon must intersect with two other segments at their endpoints. Lastly , they enclose space in a plane. These figures ARE NOT polygons. Does not close space and does not have segments joined with the endpoints of two other segments. No sides or vertices

7. POLYGONS – Introduction A polygon is closed plane figure with three or more sides. A stop sign is an example of a polygon. It has vertices and no segments intersect. All segments of the polygon must intersect with two other segments at their endpoints. Lastly , they enclose space in a plane. These figures ARE NOT polygons. Sides intersect. Does not close space and does not have segments joined with the endpoints of two other segments. No sides or vertices

8. POLYGONS – Introduction Polygons are named by their number of sides. The more familiar ones have 3, 4, 5, and 8 sides. The word polygon comes from the Greek language meaning “many angles”. Hence a triangle, “tri” means three, has three angles. STOP

9. POLYGONS – Introduction Polygons are named by their number of sides. The more familiar ones have 3, 4, 5, and 8 sides. The word polygon comes from the Greek language meaning “many angles”. Hence a triangle, “tri” means three, has three angles. Let’s name all the polygons from 3 – 10 sides. 4 3 6 5 7

10. POLYGONS – Introduction Polygons are named by their number of sides. The more familiar ones have 3, 4, 5, and 8 sides. The word polygon comes from the Greek language meaning “many angles”. Hence a triangle, “tri” means three, has three sides. Let’s name all the polygons from 3 – 10 sides. 8 9 9 10

11. POLYGONS – Introduction Polygons are named by their number of sides. The more familiar ones have 3, 4, 5, and 8 sides. The word polygon comes from the Greek language meaning “many angles”. Hence a triangle, “tri” means three, has three sides. AFTER 10, just throw the number on front of the word “gon” An “n – gon”… 8 9 9 10

12. POLYGONS – Introduction Polygons are classified as convex or concave. Convex - the easiest way to describe a convex polygon is it doesn’t collapse on itself. If I would extend the sides of the polygon, none of them would cut through the interior of the polygon.

13. POLYGONS – Introduction Concave - these polygons collapse on themselves. They look like they have a “notch” in them. When I extend the sides, the line cuts through the polygon.

14. POLYGONS – Introduction Concave - these polygons collapse on themselves. They look like they have a “notch” in them. When I extend the sides, the line cuts through the polygon. Also, two vertices of the polygon can be connected “outside” of the polygon.

15. POLYGONS – Introduction Regular Polygons - convex - all sides are equal length ( equilateral ) - all angle measures are equal ( equiangular )

16. POLYGONS – Introduction Regular Polygons - convex - all sides are equal length ( equilateral ) - all angle measures are equal ( equiangular ) EXAMPLES :

17. POLYGONS – Introduction Irregular Polygons - convex OR concave - sides are not equal in length - all angle measures are NOT equal

18. POLYGONS – Introduction Irregular Polygons - convex OR concave - sides are not equal in length - all angle measures are NOT equal EXAMPLES :

19. POLYGONS – Introduction To work with polygons we need to label them. When labeling their vertices, start at one vertice and then move clockwise in consecutive order. Don’t skip letters. A B C D

20. POLYGONS – Introduction To work with polygons we need to label them. When labeling their vertices, start at one vertice and then move clockwise in consecutive order. Don’t skip letters. A B C D To name polygons, state their vertices in order. - polygon ABCD

21. POLYGONS – Introduction To work with polygons we need to label them. When labeling their vertices, start at one vertice and then move clockwise in consecutive order. Don’t skip letters. A B M C D To name polygons, state their vertices in order. - polygon ABCD - polygon MNO O N

22. POLYGONS – Introduction Once the polygons are labeled, you can reference the polygons sides and angles. A B M C D O N

23. POLYGONS – Introduction Once the polygons are labeled, you can reference the polygons sides and angles. Side AB A B Angle M M C D O N