polygon slide

MATHEMATICS FORM 1POLYGON

SITI NORHASMIRA BINTI NORDIND20111048185

POLYGON

MATHEMATICS FORM 1

WHAT IS POLYGON???

Polygon

Made of straight lines, and the shape

is “closed”

Bounded by three or more sides

Straight line sides meet at

point called a vertex

Line that joins two

non-adjacent

vertices of polygon is called a diagonal

Which of following are polygon? Why?

POLYGON because have straight sides and enclosed

NOT A POLYGON because not enclosed figure

NOT A POLYGON because has a curve

Side

How many sides ???

512

4 0

Vertex

Vertices

Diagonal

Vertex

Vertices

Diagonal

Side

Type of polygon

I have 3 straight sides.I have 3 vertices.

What shape am I?

I’m a triangle!

TRIANGLE

Equilateral Triangle

Three equal sides Three equal angles,

always 60°

Isosceles Triangle

Two equal sides Two equal angles

Scalene Triangle

No equal sides No equal angles

I have 4 straight sides.I have 4 vertices.

What shape am I?

I’m a quadrilateral!

QUADRILATERAL

Quadrilateral just means "four sides" (quad means four, lateral means side).

Any four-sided shape is a Quadrilateral.

But the sides have to be straight, and it has to be 2-dimensional.

QUADRILATERAL

I am a pentagon!

I have 5 straight sides.I have 5 vertices.

What shape am I?

PENTAGON

Regular Pentagon

Irregular Pentagon

Irregular Pentagon

Irregular Pentagon

I have 6 straight sides.I have 6 vertices.

What shape am I?I am a hexagon!

HEXAGON

Regular Hexagon Irregular Hexagon

Irregular Hexagon

I am anheptagon!

I have 7 straight sides.I have 7 vertices.

What shape am I?

HEPTAGON

Irregular Heptagon

Irregular Heptagon

Regular Heptagon

I have 8 straight sides.I have 8 vertices.

What shape am I?I am anoctagon!

OCTAGON

Irregular Octagon

Irregular Octagon

Regular Octagon

Symmetry

• An object is said to have line(s) of symmetry if one side of it overlaps exactly with the other.

Line of symmetry(diagonal)

Line of symmetry(vertical)

Line of symmetry(horizontal)

EXERCISE

1. Which of the following is a correct definition of a polygon?

A . A closed plane figure with 3 or more straight edges as its sides.

B. A figure with 3 or more straight edges.

C. A closed figure with either straight or curved edges as its sides.

D. A plain figure with 3 or more straight edges as its sides.

2. Name the polygon

A. Triangle

B. Quadriangle

C. Hexagon

D. Quadrilateral

3. Identify the polygon(s)

A B

CD

4. Which of the following are NOT polygons

A B

C D