Do Now  

Section 8.1: Objective: SWBAT find angle measures in polygons Geometry Section 8.1: Objective: SWBAT find angle measures in polygons

Vocabulary Polygon: Diagonal: Regular Polygon: A closed plane figure with the following properties: 1. formed by 3 or more line segments called sides 2. each side intersects exactly two sides one at each endpoint, so that no two sides with a common endpoint are collinear. A segment that joins two nonconsecutive sides A polygon that has all sides, and all angles congruent

Degrees in a convex polygon Picture Name # sides # diagonals (from 1 vertex) # triangles Total interior degrees Triangle 3 Quadrilateral 4 Pentagon 5 Hexagon 6 Heptagon 7

Degrees in a convex polygon Picture Name # sides # diagonals # triangles Total interior degrees Octagon 8 Nonagon 9 Decagon 10 Dodecagon 12 N-gon n

Formulas/Notes Total interior degrees in a convex polygon = Each interior angle of a polygon = Total exterior degrees in a convex polygon = Each exterior angle of a polygon =

Find the sum of the measures of the interior angles of the indicated convex polygon. 2.) Dodecagon 3.) 40-gon

The sum of the measure of the interior angles of a convex polygon is given. Classify the polygon by the number of sides. 1.) 2520o 2.) 3960o 3.) 8640o

Find the measure of an interior angle and an exterior angle of the indicated regular convex polygon. 4.) Triangle 5.) 16-gon 6.) 60-gon

Find the value of n for each regular n-gon described. 7.) Each interior angle of the regular convex n-gon has a measure of 140 degrees. 8.) Each exterior angle of the regular convex n-gon has a measure of 45 degrees.

Find the value of n for each regular n-gon described. 32.) Each interior angle of the regular convex n-gon has a measure of 172 degrees. 34.) Each exterior angle of the regular convex n-gon has a measure of 3 degrees.