Warm Up Draw a large aerial view of a group of building into your notebook. Example:

6.1 a

A polygon is a closed figure formed by a finite number of coplanar segments such that: 1. the sides with a common endpoint are non-collinear. 2. each side intersects exactly two other sides, but only at their endpoints.

Diagonals A diagonal is a line joining two non-consecutive vertices.

ConvexConcave All vertices point outward. At least one vertex points inward.

If a diagonal can be drawn outside of the polygon, then it is considered concave.

Polygons are classified by the numbers of sides they have. Number of sides n Name of Polygon Triangle Quadrilateral Pentagon Hexagon Heptagon/Septagon Octagon Nonagon Decagon Undecagon Dodecagon N-gon

Tell whether the following are polygons. If so, name it and classify it as convex or concave.

Regular Polygons A regular polygon is a convex polygon with all sides and angles congruent. It is considered both equilateral and equiangular. There are NO regular concave polygons.

Tell whether the polygon is regular or irregular. Name it, then tell whether it is convex or concave.

How to name a polygon You name a polygon by all its vertices in consecutive order.