1. Geometry Section 8.1 Find Angle Measures in Polygons

2. Angle Sums in Polygons POLYGON# OF SIDES# OF TRIANGLESSum of the measures of interior angles Triangle Quadrilateral Pentagon Hexagon Heptagon Octogon

3. Polygon Interior Angles Theorem The sum of the measures of the interior angles of a convex n-gon is: (n – 2) · 180° (number of sides – 2) times 180°

4. Interior Angles of a Quadrilateral The sum of the measures of the interior angles of a quadrilateral is 360°

5. Examples 1. Find the sum of the measures of the interior angles of an 11-gon 2. The sum of the measures of the interior angles of a convex polygon is 1440°. Classify the polygon by the number of sides.

6. Polygon Exterior Angles Theorem The sum of the measures of the exterior angles of a convex polygon, one angle at each vertex, is 360°.

7. Example A convex hexagon has exterior angles with measures 34°, 49°, 58°, 67°, and 75°. What is the measure of an exterior angle at the sixth vertex?

8. Assignment Section 8.1 Page 510 Problems # 4 - 24 even, 28, 30