The radius of a circle is 3 kilometers. What is the circle's area

Need on this geometry question. explain how you did it.

With alll of except for the 2 that i did already

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?