The area of any circle is equal to 
, where r is the radius.
We know that the diameter is 12. The radius is always half of the diameter, so the radius of our circle must be 6.
Substitute 6 for r in our equation and simplify.
π6² = π6×6 = 36π in²
We know that the diameter is 12. The radius is always half of the diameter, so the radius of our circle must be 6.
Substitute 6 for r in our equation and simplify.
π6² = π6×6 = 36π in²