If you use the formula for the area of a circle which is pi x r squared and plug in the numbers the answer you should get 78.5 inches squared.
For #1, the best graph would be a line graph because this data is being described over a period of time. Line graphs best represent change over time.
For #2, the best graph would be a bar graph because you will easily be able to see the comparison between the prices in the bars. You will be able to easily see approximate differences and how many times greater or smaller.
For #3, a histogram will best display this data because there will be many scores from a football season to represent, and a histogram organizes a lot of data into intervals while still allowing us to see tendencies in the bars.