Exercise 2.2 Calculating the area of a room

#include <stdio.h>

int main(void)
{
    
    long feet = 0L; 
    long inches = 0L;
    double length = 0.0;
    double width = 0.0;
    const long inches_per_feet = 12L;
    const double inches_per_yard = 36L;
    
    // get the length of the room
    printf("Enter the length in foot and inches, whole foot first:");
    scanf("%ld", &feet);
    printf("                                 ...Now Enter the inches");
    scanf("%ld", &inches);
    length = (feet*inches_per_feet+inches)/inches_per_yard; //复制最好 
    
    //get the width of the room
    printf("Enter the width of the room in feet and inches, - whole feet first");
    scanf ("%ld", &feet);
    printf ("                                            ... now enter the inches");
    scanf ("%ld", &inches);
    width = (feet*inches_per_feet+inches)/inches_per_yard;
    
    //out put the area
    printf ("the area of the room is %.2f square yares. \n", length*width);
    return 0;
 }