3. A polygon is a plane figure. A polygon is a closed region. A polygon is formed by three or more segments as its sides. Each side of a polygon intersects only one segment at each of its endpoints. poli + gonus “many angled” What is a polygon?
12. Parts of a Polygon sides consecutive sides included angle nonconsecutive sides interior angles / vertex angles consecutive angles included side nonconsecutive angles exterior angles diagonals
18. Polygon Convexity A polygonal region is convex if any segment joining any two points of the polygon is part of the interior region. If a polygon is not convex, then its is concave.
25. Convex or Concave? Concave because a segment connecting points on the polygon that will lie in the exterior can be drawn.
26. Naming Polygons B A D C Polygons are named by writing their consecutive vertices in order, such as ABCD or CDAB for the polygon above. We cannot name the polygon as DBAC.
27. Connecting to Prior Knowledge Think of words beginning with the prefixes tri-, quad-, pent-, and oct-. Examples: triathlon, quadriplegic, pentameter, and octopus. Meanings? (words and prefixes)