Expert: Richard J. Raridon - 1/9/2009

Question
QUESTION: The diameter of a u.s. penny is 0.75 inch. Find the circumference and the area(of one side) of a penny.  Round to the nearest tenth.

If you can show me the work that would be great.

ANSWER: The circumference = (pi)D = 3.14(0.75) = 2.4 inches
the area = (pi)(D^2/4) = 3.14(0.75)^2/4 = 0.4 in^2

---------- FOLLOW-UP ----------

QUESTION: Hi what is the ^ mean and how did you get 2/4

Answer
The ^ means a power, D^2 means D squared, or D*D. If you were writing it out, you'd just put a little 2 to the upper right of the D, but that's not convenient with a typewriter.    
the area of a circle = (pi)r^2 where r is the radius.  Since the diameter = 2r the area can also be calculated as (pi)D^2/4