Circles

Page
1

Slide 1

The Circle

By Ranjana

Slide 2

Circle

O

A

Eg. ball,bangle,lemon.coin

Slide 3

O

A

CENTRE : O

RADIUS : OA

B

CENTRE

RADIUS

Slide 4

.

O

In a plane,each point of the circle is at equal distance from a fixed point.The fixed point is called the centre of the circle.

CENTRE = O

Slide 5

O

The distance from centre to any point on the circle is called radius of the circle.

A

RADIUS = OA

Radius

Slide 6

.

O

DI AMETER

A Line segment passing through the centre of the circle and whose end points lie on the circle is called the diameter of the circle.

A

B

DIAMETER = AB

Slide 7

Circumference

.

O

The length of the circle or the distance around it is called circumference of the circle.

Slide 8

.

O

A

B

A Line segment whose both the ends touches the circumference and passes through the centre is called diameter.

DIAMETER : AB

Slide 9

Relation between radius and diameter

.

O

A

B

RADIUS = DIAMETER

2

OB = AB

2

Slide 10

Eg. If diameter of the circle is 10 cm then find its radius?

.

O

Diameter = 10cm

Sol. Radius =diameter / 2 radius=10 cm/ 2 radius =5 cm

A

B

Slide 11

.

O

Eg. If radius of the circle is 6 cm,then find the diameter of the circle?

Radius = 6cm

A

Sol. Diameter = 2 x Radius

Diameter = 2 x 6cm

Diameter = 12 cm

Slide 12

Relation between circumference and diameter

.

O

CIRCUMFERENCE

DIAMETER

CIRCUMFERENCE = 3 x DIAMETER(APPROX)

A

B

Slide 13

Eg. Find the circumference (approx) of the circle whose diameter is 10cm.

.

O

CIRCUMFERENCE

DIAMETER=10 CM

Sol. Circumference = 3 x diameter(approx)