Question

find the circumference of circle whose area is 4time the area of circle with diameter 21cm​

Answer 1

Answer:

I hope this helps you

Step-by-step explanation:

lets name the circles a and b

diameter of circle b = 21cm

circumference of circle = πd or 2πr

here we have diameter so we will use πd formula:---

circumference of circle b = $\frac{22}{7}$ × 21

                                          = 66cm

circumference of circle a = 4 times circumference o circle b

                                          = 4 × 66

                                          = 284cm

Answer 2

Thanks. Hope it helps .

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