BASIC CONCEPT OF GEOMETRY

FOR CLASS IV

LINESIdentifying Different

Types of Lines

LINES

There are many different types of lines. Can you think of any?

verticalhorizontaldiagonal

perpendicularparallel

LINESVertical lines run from top to bottom (or up and down).

How many vertical lines can you count?

four

LINES

Horizontal lines run from side to side.

How many horizontal lines can you count?

two

LINES

Diagonal lines run from corner to corner.

How many diagonal lines can you count?

two

LINES

On your white-boards, count the number of vertical, horizontal and diagonal lines.

V –

H –

D –

6

2

5

LINES

On your white-boards, count the number of vertical, horizontal and diagonal lines.

V –

H –

D –

6

2

5

LINES

On your white-boards, count the number of perpendicular, parallel and oblique lines.

Pe –

Pa –

O -

10

8

2

LINES, LINE SEGMENTS, RAYS AND ANGLES

WHAT IS A LINE? A line is a straight path that goes on forever in both directions.

WHAT IS A LINE? raight paA line is a stth that goes on forever in both directions.

PARTS OF A CIRCLECIRCLE

THE OUTSIDE OF THE CIRCLE IS CALLEDcircumference

The circumference is the distance around the circle.

THE MIDPOINT OF A CIRCLE IS

centre

THE LINE DRAWN FROM THE CENTRE TO THE CIRCUMFERENCE IS …

radius

THE LINE DRAWN FROM ONE CIRCUMFERENCE THROUGH THE CENTRE TO ANOTHER CIRCUMFERENCE IS …

radius

diameter

The diameter cuts the circle in half!

A LINE THAT CONNECTS ONE POINT ON THE EDGE OF THE CIRCLE WITH ANOTHER POINT ON THE CIRCLE IS CALLED ….

chord

The chord that passes through thecentre of the circle is the diameter.

A SEGMENT IE. PART OF THE CIRCUMFERENCE OF THE CIRCLE IS CALLED AN ...

a r c

PARTS OF THE CIRCLE

centreradius

diameter

chord

arc

POLYGON SONG

The_Polygon_Song_-_YouTube.flv