1. Angle Relationships in Polygons
# of sides (n) 3 4 5 6 7 8 9 10
# of diagonals from one vertex
# of triangles in polygon
interior angles
exterior angles
triangle
quadrilateral
pentagon
hexagon
heptagon
octagon
nonagon
decagon 1 2 3 4 5 6 7 2 3 4 5 6 7 8
180
360
540
720
900
1080
1260
1440
360
360
360
360
360
360
360
360

2. Time to Graph...

3. y = m x + b
Sum
180 n
-360 =
Sum=180(n-2)

4. Example 1:
Find the sum of the interior angles of a dodecagon (a figure with 12 sides).
Rock on!

5. Example 2:
Find the measure of each interior angle in a regular octagon.
A regular polygon has equal sides and equal interior angles.

6. Example 3:
How many sides does a polygon have if each of its interior angles measures 140?
Have to sub. something in here
This is what we are trying to find
There are ‘n’ angles, and each one measures 140
How could you represent the sum of all the interior angles?