Question

6. If the difference between the circumference and diameter of a circle is 30 cm, then what is the radius of
the circle?
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Answer 1

Required Answer:-

The difference between the circumference and diameter of a circle is 30 cm. And we have to determine the radius of the circle.

We know that:

• Circumference = 2πr
• Diameter = 2r

Then,

⇒ 2πr - 2r = 30 cm

⇒ 2r(π - 1) = 30 cm

⇒ 2r(22/7 - 1) = 30 cm

⇒ 2r × 15/7 = 30 cm

⇒ 2r = 30 × 7/15 cm

⇒ 2r = 14 cm

⇒ r = 7 cm

Therefore:

• The radius of the given circle is $\underline{\bold{7 \: cm}}$

Answer 2

Answer:

7.05 approximately

Step-by-step explanation:

circumference of a circle ⭕= 2 π r

diameter = 2r

given: 2 π r - 2 r = 30

=> 2r (π-1) = 30

=> 2r (22/7 - 1) = 30

=> 2r × 15/7 = 30

=> 2r = 30 ×7/15

=> r= 14/2

=> r = 7cm