Assume r is a user-define value, write a C++ program to:

Create a function, doubleR, that will double the value of r. Create a function, perimeter, that will compute the perimeter of circle with radius r. Create a main function what will i) print the address of r; ii) pass r to perimeter and print the perimeter value; and iii) double the value of r using doubleR and print the perimeter value again.