PolygonsClosed figure made up of line segments

Concave Polygon-can have reflex angles :One or more angles greater than 180

o

Convex Polygon-all angles greater than 0o and less than 180

o

congruentSame size and same shape

similarSame shape, not necessarily the same

size

Regular Polygons

Polygon with all sides congruent and all angles congruent

Special Regular Polygons

Equilateral triangle

Square

TrianglePolygon with three sides

A

B

C Symbol: ABC

Quadrilateral Polygon with four sides

quadrilateral

trapezoid parallelogram

rectanglerhombus

square

kite

Parallelogra

mQuadrilateral with opposite sides parallel and congruent

Rectangle Parallelogram with four

right angles

Rhombus Parallelogram with four

congruent sides

SquareParallelogram with four right angles

and four congruent sides

TrapezoidQuadrilateral with one pair of

parallel sides

Pentagon Polygon with five sides

Regular Pentagon

HexagonPolygon with six sides

Regular Hexagon

HeptagonPolygon with seven sides

Regular Heptagon

OctagonPolygon with eight sides

Regular Octagon

DecagonPolygon with ten sides

convexconcave

DodecagonPolygon with twelve sides

concave convex

Total Degrees in Polygons

Figure Sides

3 # of triangles

1 x 180 =

Total degrees

1800

4 2 x 180 = 3600

5 3 x 180 = 5400

180

180

180

180

180

180

Complete the TableDo you see a pattern?

Figure Total degrees

# of triangles

Sides

78

6

n12

Regular Polygons

All sides congruent All angles congruent

Angle Measure Regular Polygons

What is degree measure of each angle of a regular polygon?

Total degrees = ??A

B C

D

E

Degrees = ???

ABCDE 1080

5400

Angle Measure Regular PolygonsEquilateral triangle = 1800 Measure each angle = 600

Square = 3600 Measure each angle = 900

Angle Measure Regular Polygons

Regular Hexagon = ?? Measure each angle = ??Regular Octagon = ?? Measure each angle = ??

Polygons

The End