TODAY IN GEOMETRY…

Learning Goal: 1.6 Classify Polygons

Independent Practice – NO A.T.

A

CD

E

B

vertex

sides Polygons are named by listing vertices in consecutive order:

ABCDEBCDEACDEABDEABCEABCD

POLYGON: a closed plane figure formed by three or more line segments.

interior

No lines that contain the sides goes through the interior of the polygon.

CONVEX POLYGON: polygon with all interior angles less than .

interiorOne or more lines that contain the sides, goes through the interior of the polygon.

CONCAVE POLYGON: polygon with one or more interior angles greater than .

1.

4.3.

2.

Not a polygon Convex polygon

Not a polygon Concave polygon

PRACTICE: Tell whether the figure is a polygon and whether it is concave and convex.

Number of sides Type of Polygon Number of

sides Type of Polygon

3 Triangle 8 Octagon

4 Quadrilateral 9 Nonagon

5 Pentagon 10 Decagon

6 Hexagon 12 Dodecagon

7 Heptagon n n-gon

**Name any polygon larger than 12 sides with n-gon.Example: 14 sided polygon is a 14-gon

NAMING POLYGONS: polygons are named by the number of sides they have.

Equilateral hexagon

EQUILATERAL POLYGON: polygon with all congruent sides.

Equiangular hexagon

EQUIANGULAR POLYGON: polygon with all congruent interior angles.

Regular Pentagon

EQUIANGULAR POLYGON: a convex polygon that is both equilateral and equiangular.

1. 2.

Regular hexagonEquilateralEquiangular

QuadrilateralNot equilateralNot equiangular

PRACTICE: Classify the polygons by the number of sides. Tell whether the polygon is equilateral, equiangular, or regular.

3 𝑥+6

4 𝑥−2

Sides of a regular hexagon are congruent:

Substitute x to find one length:

PRACTICE: Find the length of one side of the regular hexagon.

HOMEWORK #7:

Pg. 44: 3-13, 15-17, 24-30

If finished, work on other assignments:

HW #1: Pg. 5: 1, 5, 8-11, 13, 15, 17-21, 27-30, 46HW #2: Pg. 12: 6-16, 21-28, 33, 35HW #3: Pg. 19: 5-19, 25-27HW #4: Pg. 20: 31-34, 43-45, 50-52HW #5: Pg. 29: 7-27, 33-38, 45, 47, 50, 52, 62HW #6: Pg. 38: 4-43 odd, 46-52