1. Do Now

2. Section 8.1: Objective: SWBAT find angle measures in polygons
Geometry
Section 8.1:
Objective: SWBAT find angle measures in polygons

3. Vocabulary Polygon: Diagonal: Regular Polygon:
A closed plane figure with the following properties:
1. formed by 3 or more line segments called
sides
2. each side intersects exactly two sides one at
each endpoint, so that no two sides with a
common endpoint are collinear.
A segment that joins two nonconsecutive sides
A polygon that has all sides, and all angles congruent

4. Degrees in a convex polygon
Picture
Name
# sides
# diagonals (from 1 vertex)
# triangles
Total interior degrees
Triangle 3
Quadrilateral 4
Pentagon 5
Hexagon 6
Heptagon 7

5. Degrees in a convex polygon
Picture
Name
# sides
# diagonals
# triangles
Total interior degrees
Octagon 8
Nonagon 9
Decagon 10
Dodecagon 12
N-gon n

6. Formulas/Notes Total interior degrees in a convex polygon =
Each interior angle of a polygon =
Total exterior degrees in a convex polygon =
Each exterior angle of a polygon =

7. Find the sum of the measures of the interior angles of the indicated convex polygon.
2.) Dodecagon
3.) 40-gon

8. The sum of the measure of the interior angles of a convex polygon is given. Classify the polygon by the number of sides.
1.) 2520o
2.) 3960o
3.) 8640o

10. Find the measure of an interior angle and an exterior angle of the indicated regular convex polygon.
4.) Triangle
5.) 16-gon
6.) 60-gon

11. Find the value of n for each regular n-gon described.
7.) Each interior angle of the regular convex n-gon has a measure of 140 degrees.
8.) Each exterior angle of the regular convex n-gon has a measure of 45 degrees.

12. Find the value of n for each regular n-gon described.
32.) Each interior angle of the regular convex n-gon has a measure of 172 degrees.
34.) Each exterior angle of the regular convex n-gon has a measure of 3 degrees.