Question

cumference of the circle whose radius is :
(iii) 7.0 cm
(ii) 5.6 cm
cumference of the circle whose diameter is :
(iii) 9.8 cm
(ii) 7 cm
ius of the circle whose circumference is :
(ii) 132 cm (iii) 264 cm
igure given below and answer the following
ti2​

Answer 1

Answers:

Part 1:

Find the circumference of a circle of radius:

i) 7 cm

Circumference = 2πr

$\sf{=2\times\dfrac{22}{7}\times7}$

$\sf{=22\times2}$

$\sf{=44cm}$

ii) 5.6 cm

Circumference = 2πr

$\sf{=2\times\dfrac{22}{7}\times5.6}$

$\sf{=44\times0.8}$

$\sf{35.2cm}$

Part 2:

Find the circumference of a circle whose diameter is:

i) 9.8 cm

Radius = 9.8/2 = 4.9 cm

Circumference = 2πr

$\sf{=2\times\dfrac{22}{7}\times4.9}$

$\sf{=44\times0.7}$

$\sf{30.8cm}$

ii) 7 cm

Radius = 7/2 = 3.5 cm

Circumference = 2πr

$\sf{=2\times\dfrac{22}{7}\times3.5}$

$\sf{=44\times0.5}$

$\sf{=22cm}$

Part 3:

Find the radius of the circle whose circumference is:

i) 132 cm

Circumference = 2πr

$\sf{2\times\dfrac{22}{7}\times\:r=132cm}$

$\sf{r=132\times\dfrac{1}{2}\times\dfrac{7}{22}}$

$\sf{r=3\times7}$

$\sf{r=21cm}$

ii) 264 cm

Circumference = 2πr

$\sf{2\times\dfrac{22}{7}\times\:r=264cm}$

$\sf{r=264\times\dfrac{1}{2}\times\dfrac{7}{22}}$

$\sf{r=6\times7}$

$\sf{r=42cm}$

Answer 2

Part 1:

Find radius:

the circumference of a circle of

i) 7 cm

Circumference = 2tr

= 2 x 22 7 x 7

= 22 x 2

= 44cm

ii) 5. 6 cm

Circumference = 2ttr

= 2 x 22 7 x 5.6

= 44 x 0.8

35.2cm

Part 2:

Find the circumference of a circle whose diameter is:

i) 9.8 cm

Radius = 9. 8/2 = 4.9 cm

Circumference = 2tr

= 2 X 22 7 X 4.9

= 44 x 0.7

30.8cm

ii) 7 cm

Radius = 7/2 = 3. 5 cm

Circumference = 2Ttr

= 2 x 22 7 х 3.5

= 44 x 0.5

= 22cm

Part 3:

Find the radius of the circle whose circumference is :

i) 132 cm

Circumference = 2tlr

2 x 22 7 x r= 132cm

1 r=132 x х 2 22

r= 3 x 7

r=21cm

ii) 264 cm

Circumference = 2Ttr

2 x22/7

xr=264cm

r= 264 x

r=6 x 7

r= 42cm