Answer:
circumference = 37.68 (37.7 if you're rounding it)
Area = 113.04 (113.1 if you're rounding it)
Explanation:
The formula for circumference is C=2πr (2 times pi times radius)
If the diameter is 12, the radius is 6.
2 x 3.14 x 6 = 37.7
The formula for area is A=πr2 (pi x radius to the second power)
The radius is 6. Six to the second power is 36.
36 x 3.14 = 113.04