Tins in a box

#include <stdio.h> //header files
#include <stdlib.h> //header files
 
float cyl_diameter,cyl_height,cyl_radius,cyl_radius2,cyl_answer,cyl_vol,total_cyl_vol,waste //Cylinder variables
float cont_height,cont_width,cont_lenght,cont_area,cont_vol,cont_answer //Container variables
int fitinbox
char buff[20]//buffer
float cylinder_vol (float cyl_height,float cyl_diameter) //Work out 
{
	cyl_radius = cyl_diameter / 2 // calculate radius 
	cyl_radius2 = cyl_radius*cyl_radius //calculate  radius squared
	cyl_answer= 3.14*cyl_radius2*cyl_height//calculate volume 
	return cyl_answer//return area to main function 
 
}
 
float container_vol(float lenght,float height,float width) //works out the container volume
{
	cont_answer= lenght*height*width
	return cont_answer
}
int amount_fits(float diameter,float lenght,float width,float height) //works out the amount of cylinders that fits in a box
{
	int answer
	answer = (int)(lenght / diameter) * (int)(width / diameter) * (int)(height / cyl_height)
	return answer
}
void main ()
{
	do{
		printf ("Enter the height of the Cylinder in CM: ") 
		cyl_height = atof(gets(buff))
			if (cyl_height <=0)
			{
			printf("Height Entered is To low.\n")
			}
	}while(cyl_height <=0)
	do{
		printf ("Enter the diameter of the Cylinder in CM: ")
		cyl_diameter = atof(gets(buff))
			if (cyl_diameter <=0)
			{
			printf("Diameter Entered is To low.\n")
			}
	}while(cyl_diameter <=0)
	do{
		printf ("Enter the Width of the box in CM: ")
		cont_width = atof(gets(buff))
			if (cont_width <=0)
			{
			printf("Width Entered is To low.\n")
			}
	}while(cont_width <=0)
	do{
		printf ("Enter the Length of the box in CM: ")
		cont_lenght = atof(gets(buff))
			if (cont_lenght <=0)
			{
			printf("lenght Entered is To low.\n")
			}
	}while(cont_lenght <=0)
	do{
		printf ("Enter the Height of the box in CM: ")
		cont_height = atof(gets(buff))
			if (cont_height <=0cyl_height > cont_height)
			{
			printf("Height Entered is To low.\n")
			}
	}while(cont_height <=0cyl_height > cont_height)	
	/*The above code Gets input from user and makes sure the input is above 0 if not it will
	tell the use thir is an error and show the input prompt again*/
 
	cyl_vol = cylinder_vol(cyl_height,cyl_diameter) // calls function to work out cylinder volume
	cont_vol= container_vol(cont_lenght,cont_height,cont_width)//calls function to work out container volume
	fitinbox = amount_fits(cyl_diameter, cont_lenght, cont_width, cont_height) 
	// above calls function to work out the amount of tins that fit in a box
	total_cyl_vol = cyl_vol * fitinbox // this works out the total volume used inside the box by the tins
	waste = cont_vol - total_cyl_vol //this takes the total volume used by the tins and takes it from the box volume
 
	printf("You can fit %d cylinders in box\n",fitinbox) //Shows user the program output 
	printf ("The waste volume is: %2.2f CM3\n",waste)
 
 
}