1. Warm Up 9/21 What is the measure of each angle in a regular octagon?
Supplies Needed:
Calculator
What is the measure of each angle in a regular octagon?
Draw a picture of the following:
A concave quadrilateral
A convex nonagon
A regular quadrilateral

2. Reset your password! It is somehow expiring.
Infinite Campus
Reset your password! It is somehow expiring.

3. Homework Answers pg. 1090 (1-7)

6. Homework Answers Angle Chasing Worksheet 1. a = 122° 2. b = 136°
3. c = 108° d = 106°
4. e = 108° f = 36°
5. g = 105° h = 82°
6. j = 120° k = 38°

7. Objective:
Explore Interior and Exterior Angles

8. Review: Interior Angles
An interior angle is an angle formed by two sides of a polygon with a common vertex.
A triangle has three interior angles

9. Review
Find the sum of the interior angle measures of a convex heptagon.
900°
2. Find the measure of each interior angle of a
regular 16-gon.
If a polygon has an interior angle sum of 1800o, what type of polygon is it?
Dodecagon

10. Review Find the measure of each interior angle of pentagon ABCDE.
mA = 35(4) = 140°
mB = mE = 18(4) = 72°
mC = mD = 32(4) = 128°

11. Each exterior angle has two remote interior angles
Each exterior angle has two remote interior angles. A remote interior angle is an interior angle that is not adjacent to the exterior angle.
4 is an exterior angle.
The remote interior angles of 4 are 1 and 2.
Exterior
Interior
3 is an interior angle.

12. What is the relationship between angle 4 and angles 1 and 2?
Exterior
Interior
pg. 1087

13. Write a Paragraph Proof!
pg. 1087

14. 50°
115°
65° 3 4

15. Find mB
x = 26
mB = 2x + 3 = 2(26) + 3 = 55°

16. Your turn! pg and 12

19. Find the measure of all exterior angles.
What is their sum?

20. Find the measure of all exterior angles.
What is their sum?

22. Find the measure of each exterior angle of a regular 20-gon.
A 20-gon has 20 sides and 20 vertices.
sum of ext. s = 360°.
measure of one ext.  =
The measure of each exterior angle of a regular 20-gon is 18°.

23. Find the value of b in polygon FGHJKL.
15b° + 18b° + 33b° + 16b° + 10b° + 28b° = 360°
120b = 360
b = 3

24. Homework
Pg (10-15, 13 should be 6x -1)