AREA!!!
To find the area of a circle, you use the equation pi r squared
since the diameter is 12, the radius is 6. So r squared is 36, multiplying that by pi we get
inches squared.
CIRCUMFERENCE!!
The formula for finding the circumference is pi d or pi times diameter
Doing that we get
inches squared.
Normally, schools and tests with have pi as 3.14, so you could add that into the equations, but only if it asks for you to. These solutions are only if the question didn't say anything about using 3.14 instead of pi.
Any questions?