1. 1.6 Two Dimensional Figures
By the end of class you will be able to classify polygons and calculate their perimeters.

2. What is a polygon?
Polygons:
Not Polygons:

3. Polygons:
Closed figure formed by a finite number of coplanar segments such that:
The sides that have a common vertex are not collinear
Each side intersects exactly two other sides, but only at their endpoints

4. Types of Polygons
# Sides
Name 3 4 5 6 7 8 9 10 11 12 n

5. Classifying Polygons
Convex
Concave

6. Angles and Sides Equilateral Polygons Equiangular Polygons
All Sides are congruent
All Angles are congruent

7. Regular Polygons:
Have congruent sides and congruent angles

8. Practice: Draw it A: A regular quadrilateral B: An irregular pentagon
C: A concave octagon
D: A convex hexagon

9. Perimeter and Circumference
Perimeter-distance around an object
How do you calculate it?
-Perimeter of a circle??

10. Calculate the perimeters
A square with a side that measures 5in
A rectangle with a length of 3m and a width of 9cm.
A circle with a radius of length 6m.

11. Find the perimeter

12. Find the perimeter of pentagon ABCDE that has the following vertices: A: (0, 4) B: (4,0) C: (3, -4) D: (-3, -4) E: (-3, 1)

13. The width of a rectangle is 5 less than twice its length
The width of a rectangle is 5 less than twice its length. The perimeter is 80cm. Find the dimensions.