Question

The area of a circle is 16pi cm2. What is the circle's circumstance?

2pi cm
4pi cm
8pi cm
16pi cm

Answer 1

I think you mean circumference...Area is
`A= \pi r^(2)`. We have the area so we need to use it to solve for the radius which we will then use in the circumference formula.
`16 \pi = \pi r^(2)`. Divide both sides by pi to get
`(16 \pi )/( \pi ) = r^(2)`. Of course the simplification of the left side gives us
`16= r^(2)` and r = 4. Now fill that in to the circumference formula, which is
`C=2 \pi r`, to get C
`C=2 \pi (4)` which is a circumference of
`8 \pi`