Classifying polygons Chapter 1

Homework Quiz! Angle 1 and angle 2 are supplementary. The measure of angle 1=97°, find the measure of angle 2. Angle 3 and 4 are complementary. If the measure of angle 3=74°, find the measure of angle 4. Find the measure of angle EFH.

Identifying Polygons A polygon is a closed figure with the following properties: It is formed by three or more line segments called sides. Each side intersects exactly two sides, one at each endpoint. Each endpoint of a side is called a vertex of the polygon. Multiple vertex are called vertices. We name polygons by listing the vertices

Convex and Concave Convex: no line that lies on a side of the polygon contains a point in the interior of the polygon Concave: a line that lines on the side of the polygon contains a point in the interior of the polygon (not convex)

Decide whether each figure is a polygon Decide whether each figure is a polygon. If it is, is it convex or concave? 1 3 2 4

Classifying Polygons We name polygons based on the number of its sides:

N-gons The term n-gon, where n represents the number of a polygon’s sides, can also be used to name a polygon Example: a polygon with 14 sides is a 14-gon

Types of Polygons Equilateral polygon: all sides congruent Equiangular polygon: all angles in the interior are congruent Regular polygon: convex polygon that is both equilateral and equiangular

Explain whether the polygon is equilateral, equiangular, or regular 1. 3. 2.

Sketch an example of a convex heptagon and an example of a concave heptagon.

Finding side lengths A table is shaped like a regular hexagon. The expressions shown represent side lengths of the hexagonal table. What is the length of each side? (3x+6) in (4x-2) in

Things to remember A polygon is formed by _________ or more lines. Convex: Concave: Regular: