To solve this problem, we need to remember the two possible formulas for finding the circumference of a circle, which are: C = 2πr and C=πd.
Because we are given the diameter in this example, we should use the C=πd formula. To solve, we simply need to plug in our value for the variable d (representing diameter).
C = πd
C = π(12 inches)
C = 12π inches, or approximately 37.68 inches (found by plugging in 3.14 for pi)
Therefore, the circumference is 12π or 37.68 inches.
