Instructions:

Create a def $($function$)$ called carea that will accept a single floating point number representing the circle's

radius. Have the function calculate and return the surface area of a circle using the the calculation that area

is the radius squared times pi$.$

Create a def called main that calls the def carea and print the results twice. Once for a circle with a radius

of $1$ and again for a circle with a radius of $9\mathrm{.}5.$

Call main at the bottom of your code to start the program.

Python has pi built in$.$ Import the math library and use math.pi in your calculation for pi$.$