1. Std. :- 5th
Sub. :- Mathematics
Chapter no. 19
Circle

2. Note :- Remember we can draw many radii & many diameters of a circle.
Point o is the centre of the circle .
Diameter :- A segment joining the points on the circle passes through the centre of the circle is known as diameter. o P Q A
In fig. seg PQ is a diameter.
Radius :- The segment joining the centre & any point on the circle is known as radius
In fig. seg OA is a radius.
Note :- Remember we can draw many radii & many diameters of a circle.

3. To draw a circle of a given radius using a compass.
Video clip

4. Draw a circles of the given radii
Draw a circles of the given radii. Show the diameter & the radius of each circle
2.5 cm
3 cm
3.5 cm
4.2 cm
3.8 cm

5. B C D A
Measure the lenth of the radius AB & the diameter CD
Radius AB = 1.5 cm
Diameter CD = 3 cm

6. Sr No Radius Diameter 1 2cm 4cm 2 3cm cm 3 2.2cm
Draw the circles of radius 2cm, 3cm, 2.2 cm, 3.5 cm in your notebook. Draw the diameter of each circle.Measure the lengths of diameters & complete the following table.
Sr No
Radius
Diameter 1
2cm
4cm 2
3cm cm 3
2.2cm
Observe the table. What is your conclusion?

7. Diameter of a circle = radius * 2
Radius of a circle = diameter / 2

8. What is the length of the diameter of a circle of radius 4 cm ?
Solution :-
Radius = 4 cm
Diameter = radius * 2
= 4 * 2
= 8 cm
The length of the diameter of a circle is 8 cm

9. Solve the following examples : -
1) What is the length of the diameter of a circle of radius 4.3 cm ?
2 ) What is the length of the radius of a circle of diameter 9 cm ?
3 ) What is the length of the diameter of a circle of radius 3.5 cm ?