4 times 3.14 times 8 squared
803.8
Most real number arithmetic is pretty vacuous

That's about as good a way as possible to write this particular real number. But it's far from the only way.

so

Sometimes you can factor something out and you have a common radical:

But most of them are vacuous,

The answer to the question
Answer: circumference = 2Πr²
Where r= 3
Π=3.14
Therefore Circumference = 2×3.14× 3²
= 2×28.26
Circumference=56.52
Formula:
Subtitute in 3 for r.
Solve and the answer is 28.26