$$ Write a program that asks a user to enter a radius value.

$$ Implement two user defined functions,$$circleArea$,$ and$$sphereVolume$$to calculate the area of the circle and volume of the sphere using the given radius.

$$ Use these equations for the calculations where $$is the radius:

o$$ Area of the Circle

o$$ Volume of the Sphere$$Hint: Be aware of the integer division problem.

$$ The mathematical constant$$ must be declared as a constant with the value of $3\mathrm{.}14159.$

$$ Both functions take one parameter of$$double$$type and return a$$double$$result$.$

$$ Write adequate preconditions and postconditions comments for both functions.

$$ The functions$$ prototypes must be declared above the main function and the definitions must be placed below the main function.

Write a main$$function that calls the two user defined functions