Question

A circle has area 441 pi cm. What is the circumference?

Answer 1

\[441 \pi = \pi r ^2 \rightarrow r = \sqrt{441} = 21\]

Answer 2

\[r = 21cm\]

Answer 3

thank you

Answer 4

subt in 2pr (circumference/perimeter of a circle), you'll get:\[C = 2 \pi r = 42 \pi cm\]

Answer 5

that's your circumference! yw :)