CLASSIFYING POLYGONSChapter 1

Homework Quiz!1. Angle 1 and angle 2 are supplementary. The measure of angle

1=97°, find the measure of angle 2.

2. Angle 3 and 4 are complementary. If the measure of angle 3=74°, find the measure of angle 4.

3. 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. If it is, is it convex or concave?

a. 1

b. 2

c. 3

d. 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.

2.

3.

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

Finding side lengthsA 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: