9.
Find the radius of a circle whose circumference is
(b) 17.6 cm
22
7
(d) 79.2 cm
(a) 22 cm
(C) 30.8 cm
in each case.]
[Take a =
Answers
Answer:
a) 3.5 cm
b) 2.8 cm
c) 4.9 cm
d) 12.6 cm
Step-by-step explanation:
Q: Find the radius of a circle whose circumference is
(a) 22 cm
(b) 17.6 cm
(c) 30.8 cm
(d) 79.2 cm
Formula used:
Circumference of a circle = 2πr
a) Given : Circumference = 22 cm
Circumference of a circle = 2πr
→ 22 = 2πr
→ 11 = πr
→ r = 11 × 7/22 = 3.5
∴ Radius = 3.5 cm
b) Given : Circumference = 17.6 cm
Circumference of a circle = 2πr
→ 17.6 = 2πr
→ 8.8 = πr
→ r = 8.8 × 7/22 = 2.8
∴ Radius = 2.8 cm
c) Given : Circumference = 30.8 cm
Circumference of a circle = 2πr
→ 30.8 = 2πr
→ 15.4 = πr
→ r = 15.4 × 7/22 = 4.9
∴ Radius = 4.9 cm
d) Given : Circumference = 79.2 cm
Circumference of a circle = 2πr
→ 79.2 = 2πr
→ 39.6 = πr
→ r = 39.6 × 7/22 = 12.6
∴ Radius = 12.6 cm
#shivam