Question

7. Find the circumference of a circle whose radius is
a) 7cm b) 8.4cm

8. Find the circumference of a circle whose diameter
a) 10.5cm b) 21cm​

Answer 1

$\bf\underline{\underline{\green{SOLUTION:-}}}$

Question 1

• Find the circumference of a circle whose radius is ?

Answer

• a) 44cm
• b) 52.8cm

Given

• a) Radius = 7cm
• b) Radius = 8.4cm

To Calculate

• Circumference

Explanation

a) Radius = 7cm

☆ Circumference = 2 π r

➥ 2×22/7×7

➥ 44

Circumference = 44cm

b) Radius = 8.4cm

☆ Circumference = 2π r

➥ 2×22/7×8.4

➥ 52.8

Circumference = 52.8

Question 2

• Find the circumference of a circle whose diameter

Answer

• a) 33cm
• b) 66cm

Given

• a) Diameter = 10.5
• b) Diameter = 21

To Calculate

• Circumference

Explanation

a) Diameter = 10.5cm

Radius = 10.5/2 = 5.25

☆ Circumference = 2 πr

➥ 2×22/7×5.25

➥33

Circumference = 33cm

b) Diameter = 21

Radius = 21/2= 10.5

☆ Circumference = 2πr

➥ 2×22/7×10.5

➥ 66

Circumference = 66cm

_________________________________________

Answer 2

Answer

a) 44cm

b) 52.8cm

Given

a) Radius = 7cm

b) Radius = 8.4cm

To Calculate

Circumference

Explanation

a) Radius = 7cm

☆ Circumference = 2 π r

➥ 2×22/7×7

➥ 44

Circumference = 44cm

b) Radius = 8.4cm

☆ Circumference = 2π r

➥ 2×22/7×8.4

➥ 52.8

Circumference = 52.8

Question 2

Find the circumference of a circle whose diameter

Answer

a) 33cm

b) 66cm

Given

a) Diameter = 10.5

b) Diameter = 21

To Calculate

Circumference

Explanation

a) Diameter = 10.5cm

Radius = 10.5/2 = 5.25

☆ Circumference = 2 πr

➥ 2×22/7×5.25

➥33

Circumference = 33cm

b) Diameter = 21

Radius = 21/2= 10.5

☆ Circumference = 2πr

➥ 2×22/7×10.5

➥ 66

Circumference = 66cm