Finding Angles in Polygons Notes

1. Name:___________________________________________________ Date:__________ Hour:__________
Notes Sec. 8.1: Find Angle Measures in Polygons
Note: Unless otherwise stated, the term polygon refers to a convex polygon.
Divide the following polygons into smaller triangles. Use the least number of triangles possible.
# of sides 1 2 3 4 5 6 7 8 33 n
# of
triangles
The angles of a polygon: In a polygon with n sides, the sum of the angle measures is
Ex. 1: Find the sum of the interior angle measures of an octagon.
Exterior Angles of a Polygon:
The sum of the exterior angles of any polygon is

2. Ex. 2: Find the measure of each interior angle.
x°
5x°
130°
y°
y° (7x – 70)°
Ex. 3: Find the value of z.
(7z + 120)°
(z2 + z)°
(4z + 120)° (z + 90)°