Download Day 1 PreAP Notes Angles of Polygons.notebook

Day 1 PreAP Notes Angles of Polygons.notebook
PreAP Geometry
Notes 6­1
Angles of Polygons (Using Patterns) November 30, 2015
Name_________________
Date____________Per___
Definitions
Convex Polygon
Polygon
has no angles pointing inward
a closed shape made up
*
of straight lines
Examples:
(no interior angles more than 1800)
*
Concave polygon
has a "cave" in it *
Nonexamples:
(interior angle more than 1800)
The polygons below are called regular. What is a regular polygon? 1.) For each figure count the number sides and name it according to the number of sides.
2.) Draw all possible diagonals from one vertex.
Complete the table
Convex Polygon
# of Sides
Number of Triangles
Sum of Angles
One
Angle
3
4
5
6
7
8
9
10
11
12
n
1
Day 1 PreAP Notes Angles of Polygons.notebook
November 30, 2015
Look at each pair of adjacent numbered angles ﴾such as 1 and 2 or 11 and 12﴿. What is the relationship between the two angles?
Complete the table:
Regular
Convex Polygon
Measure of Measure of # of One Interior One Exterior Sides
Angle
Angle
Sum of Exterior Angles
3
4
5
6
n
1. A convex polygon has 13 sides. Find the sum of the measures of the interior angles. 2. Find the measure of each interior angle of pentagon ABCDE.
3. Find the measure of each exterior angle in the diagram.
Find the measures of an interior angle and an exterior angle of each regular polygon. Round to the nearest tenth if necessary.
4. Dodecagon
5. 18­gon
The measure of an interior angle of a regular polygon is given. Find the number of sides in the polygon.
6. 120
7. 108
2