Chapter 1-6 (Classify Polygons)  What is a polygon?

 A closed plane figure formed by 3 or more line segments, with no two sides being collinear.

Chapter 1-6 (Classify Polygons)  Two types of polygons  Convex: All vertices going outward  Concave: A vertex going inside the polygon

Chapter 1-6 (Classify Polygons)  Example  Tell whether the following polygons are convex or concave

Chapter 1-6 (Classify Polygons)  How do you classify polygons?

 Named by the number of sides  Congruent polygons:  After 12 sides, the general name is a n-gon, where n is the number of sides    Equilateral: All sides are congruent Equiangular: All angles are congruent Regular: Convex polygon that is both

Chapter 1-6 (Classify Polygons)  Example  Classify the polygons by the number of sides. Is it equilateral, equiangular, or regular?

Chapter 1-6 (Classify Polygons)  Example

Chapter 1-6 (Classify Polygons)  Example  The expression (4x + 8)º and (5x – 5)º represent the measures of 2 of the congruent angles in the previous problem. Find the measure the an angle.