2.5 – Classify Polygons

Polygon:

2. No sides overlap or cross

3. No curved sides

1. 3 or more sides

4. Closed figure

Side: Segments that connect to form the shape

M

T

SR

Q

QM

MT

TS

SR

RQ

Vertex: Corners of the polygon

M

T

SR

Q

M

T

S

R

Q

Consecutive Sides: Sides with common point

M

T

SR

Q

and MTQM

and QRQM

Diagonal: Segment that joins two nonconsecutive vertices that go through the shape

M

T

SR

Q

QT

QS

MS

MR

TR

Convex: Every vertex points away from the center of the shape (passes rubber band test)

Concave: At least one vertex points into the shape

1. State whether the shape is a polygon. If yes, is it concave or convex? If no, why not?

Curved side

Yes, Concave or Convex

OR

No, _________________

Yes, Concave or Convex

OR

No, _________________

1. State whether the shape is a polygon. If yes, is it concave or convex? If no, why not?

Yes, Concave or Convex

OR

No, _________________

1. State whether the shape is a polygon. If yes, is it concave or convex? If no, why not?

Yes, Concave or Convex

OR

No, __________________Overlaps

1. State whether the shape is a polygon. If yes, is it concave or convex? If no, why not?

# of sides Name

3

4

5

trianglequadrilateral

pentagon

# of sides Name

3

4

5

6

7

8

9

10

11

12

n

trianglequadrilateral

pentagonhexagon

heptagonoctagon

nonagon

decagon

11-gondodecagonn-gon

Equilateral Equiangular Regular

All sides are equal

All angles are equal

All sides AND angles are equal

2. Classify the name of the polygon by the number of sides. Is the polygon equilateral, equiangular, or regular? Explain your reasoning.

Hexagon

quadrilateral

Octagon

decagon

Heptagon

Quadrilateral

3. The lengths (in feet) of two sides of a regular quadrilateral are represented by the expressions 8x – 6 and 4x + 22. Find the length of a side of the quadrilateral.

8x – 6

4x + 22

8x – 6 = 4x + 22

4x – 6 = 224x = 28x = 7

Side Length = 8(7) – 6 = 50ft