Question

Circle A has a circumference of 25 centimeters. Circle B's diameter is 3 times as long as circle A’s diameter. What is the circumference of circle B?

- And don’t say 10 because it’s wrong

Answer 1

Answer: 74.98cm

Explanation:

Step 1: Find out radius of Circle A. [We use circumference of circle A to find its radius].

Circumference of circle A = 2πr; where r is radius.

To better viewing we change sides, we get:

2πr = Circumference of circle A

2πr = 25

r =
`(25)/(2\pi )`

r =
`(25)/(3.14)`

r ≈ 3.98

Step 2: Calculate the diameter of circle A.

diameter of circle A = 2r = 2(3.98) = 7.96

Step 3: Finding diameter of circle B.

diameter of circle B = 3(diameter of circle A) = 3(7.96) = 23.88

Step 4: Converted diameter of circle B to r.

diameter of circle B = 2r

23.88 = 2r

divided 2 from both sides, we get:

11.94 = r

Step 5: Substitute radius of circle B into the circumference formula, where C = 2πr.

C = 2πr

C = 2(3.14)(11.94)

C ≈ 74.98