Final answer:
The approximate diameter of Monica's circular firepit is 3.18 feet.
Step-by-step explanation:
To find the approximate diameter of Monica's circular firepit, we need to use the formula for the circumference of a circle, which is C = π * d. Since we know the circumference (C) is 10 feet, we can substitute this value into the formula and solve for the diameter (d). Rearranging the formula, we have d = C/π. Therefore, the approximate diameter of Monica's firepit is 10/3.14 = 3.18 feet. So, the correct answer is b) 3.18 feet.
Learn more about Finding the diameter of a circle