1. 3-3 & 3-4 Parallel Lines & the Triangle Angle-Sum Theorem
The Polygon Angle-Sum Theorem

2. OBJECTIVES Classify triangles and find the measures of their angles
To use exterior angles of triangles
Classify polygons and find the sums of the measures of the interior and exterior angles of polygons

3. VOCABULARY
Exterior angle of a polygon- an angle formed by a side and an extension of an adjacent side
Remote interior angles- two nonadjacent interior angles
Polygon- a closed plane figure with at least three sides that are segments
Convex Polygon- has no diagonal with points outside the polygon
Concave Polygon- has at least one diagonal with points outside the polygon
Equilateral polygon- all sides congruent
Equiangular polygon- all angles congruent
Regular polygon- is both equilateral and equiangular

4. Postulates & Theorems