I am new to c programming and I cannot understand the teacher for the life of me. It becomes very difficult to learn this stuff even just by reading. I'd greatly appreciate any help...

The program asks for the user to input the radius and height of a right
cylinder. It then calculates surface area and volume of this cylinder
and prints the out-put on the screen in the FORMAT GIVEN BELOW. The
main program calls following three functions to accomplish the above job.
calc_area (double rad, double height)
calc_volume (double rad, double height)
and
print_info (void)

II. Helpful Math Hints:
Surface area = 2*PI*r*h + PI*r*r; and volume = PI * r*r*h

III. Helpful Programming Hints:

1. Preprocessor define PI= 3.14159
2. Declare PROTOTYPE FUNCTIONS shown above with proper return
parameters.
3. Define the three programs mentioned above, in region out-side your
main program.
3. Declare variables r, d, h, V, A as “double”.
4. Ask user to enter r in centimeters, read the value and assign to r;
ask to enter h in cms, read the value (scan in lf format) and assign
to h.
5. Call the three programs, assigning their return values
appropriately.
6. Using the results print the out-put.

IV: Output to the screen in the format:
__________________________________________________ ________________________

Enter diameter in centimeters: 3
Enter height in centimeters: 5

A right circular cylinder with a diameter = 3.00 cm and a height = 5.00
cm
will have a volume and surface area

VOLUME SURFACE AREA
------------------------------------------------------

35.3429 cu_cm 61.2610 sq_cm
Press any key to continue

Where do I even begin?!?