I need help with this.
A homeowner wants to build a circular patio. If the diameter of the patio is 20ft, what is its area to the nearest whole number.
a)1,257
b)314
c)63
d)31

Question

I need help with this. 
A homeowner wants to build a circular patio. If the diameter of the patio is 20ft, what is its area to the nearest whole number. 
a)1,257
b)314
c)63
d)31

mathmale · Answer

Let me ask you:  What's the area of a circle, if you're given the radius?
What's the area, if you're given the diameter?
Please type out the pertinent formulas.  Thx.

dengeki_daisy · Answer

A = pi * r^2 

A = 3.14 * 10^2 

A = ?