Answer:
area of circle = πr^2
just substitute 20 for r:
π(20)^2
= 400π
If the question ask for an answer in terms of pi, this is your answer. If it doesn't, simplify it further to get:
= 1256.637061 (m/cm)^2
You can round this however you like, but I would say either 3 significant figures, either 1 or 2 decimal places.
