1. Lesson 3-4
Polygons

2. A polygon is a closed figure
No, not a polygon
Yes, a polygon

3. A polygon formed by a finite number of coplanar segments
No, not a polygon
Yes, a polygon

4. No, not a polygon Yes, a polygon
A polygon has segments that intersect exactly two other sides, but only at their endpoints.
No, not a polygon
Yes, a polygon

5. Definition of a Polygon
A closed figure formed by a finite number of coplanar segments such that the segments intersects exactly two other sides, but only at their endpoints.

6. Classifications of a Polygon
Convex
Concave
Regular
Irregular

7. Convex Polygon
No line containing a side of the polygon contains a point in its interior

8. (think the opening of a cave)
Concave Polygon
the opposite of convex
(think the opening of a cave)

9. Regular Polygon
A convex polygon in which all angles have the same measure and all sides are the same length

10. Two sides (or two interior angles) are not congruent
Irregular Polygon
Two sides (or two interior angles) are not congruent

11. Polygon Names 3 sides Triangle 4 sides Quadrilateral 5 sides Pentagon
Hexagon
7 sides
Heptagon
8 sides
Octagon
9 sides
Nonagon
10 sides
Decagon
Dodecagon
12 sides
n sides
n-gon

12. a segment connecting nonconsecutive vertices of a polygon
Diagonals of a Polygon
a segment connecting nonconsecutive vertices of a polygon

13. For a convex polygon with n sides:
The sum of the interior angles is
The measure of one interior angle is
The sum of the exterior angles is
The measure of one exterior angle is