Rigor Classify polygons and find the measures of interior and exterior angles of polygons. Relevance Shapes, they are everywhere you want to be (and some places you don’t)!

A polygon is a closed plane figure formed by three or more segments that intersect only at their endpoints. Remember!

Example 1 Tell whether each figure is a polygon. If it is a polygon, name it by the number of sides. polygon, nonagon polygon, heptagon not a polygon not a polygon

Each segment that forms a polygon is a side of the polygon. The common endpoint of two sides is a vertex of the polygon. A segment that connects any two nonconsecutive vertices is a diagonal.

A polygon is concave if any part of a diagonal contains points in the exterior of the polygon. (polygon caves in) If no diagonal contains points in the exterior, then the polygon is convex (all vertices point out). A regular polygon is a convex polygon that is both equilateral (congruent sides) and equiangular (congruent angles). If a polygon is not regular, it is called irregular.

Example 2 Tell whether each polygon is regular or irregular. Tell whether it is concave or convex. irregular, convex irregular, concave regular, convex

Remember!

Example 3 Find the sum of the interior angle measures of each convex polygon. A hexagon A dodecagon A 52-gon

Example 4 Find the measure of each interior angle of pentagon ABCDE.

An exterior angle is formed by one side of a polygon and the extension of a consecutive side. Remember!

Example 5 Find the value of b in hexagon FGHJKL.

Example 6 Find the measure of each exterior angle of a regular decagon.

6-1 Classwork Textbook pg 398 #1 – 15

Primary Assignment: join.quizizz.com Codes: Honors: 6-1 Assignments Primary Assignment: join.quizizz.com Codes: Period 1: 889156 (due Thursday) Period 5: 915398 (due Thursday) Period 6: 951637 (due Friday) 6-1 Secondary Assignment: Textbook pg 398–399 #16–26, 29–31

Standard: 6-1 Assignments Primary Assignment: join.quizizz.com Codes: Period 2: 743162 (due Friday) Period 4: 689729 (due Friday) Period 7: 121722 (due Friday) 6-1 Secondary Assignment: Textbook pg 398–399 #16–26, 29–31