Please help me to write a program in C++ with comments and to keep it simple as possible.

Thank you!

Here is my program I have done before and that need to be change:

#include

#include

using namespace std;

// function prototype returning one value

double cylvol(double, double); // Note: two data types inside brackets

double surfarea(double, double); // Note: two data types inside brackets

int main()

{

double r, l, V, S;

cout

cout

cin >> r >> l;

V = cylvol(r, l); // Note: passing two numbers to function

S = surfarea(r, l);

cout

cout

system("pause");

return 0;

}

double cylvol(double r, double l) // Note: receiving two numbers

{

double V;

V = 3.14*(r*r*l);

return V;

}

double surfarea(double r, double l) // Note: receiving two numbers

{

double S;

S = 2 * 3.14*(r*l);

return S;

}

C++ Functions (20 points) Convert the following programming assignment that you have done before using C++ Class. Create constructors, set and get methods and all other necessary methods. Create your own main 0 program to thoroughly test whether your class design works well. Write a program to calculate a volume and side surface of a cylinder with a given radinus and length respectively. Write a function for each calculation. Display the results in a readable format with two decimal points. Below shows information on how to calculate the volume and the side surface of a cylinder, and how the function should be designed. Volume of cylinder The volume, V, of a cylinder is given by this formula; r is the cylinder's radius, and L is its length Using this formula, write a C++fimction named cyvol() that accepts a cylinder's radius and length and return its vohme. Surface area The side surface area, S, of a cylinder is given by this formula r is the cylinder's radius, and 1 is its length Using this formula, write a C++function named surfarea) that accepts a cylinder's radnus and length and return its side surface area