C programming :- Area of Switch Control in C Programming

#include<stdio.h>
#include<conio.h>
void main()
{
int l,b,h,r,ch,area;
printf(" 1.area of rectangle\n 2.area of circle\n 3.area of traingle\n 4.area of square\n");
printf("enter choice");
scanf("%ch",&ch);
switch(ch)
{
case 1:
printf("enter lenght and breadth of rectangle");
scanf("%d %d",&l,&b);
area=l*b;
printf("area of rectangle=%d",area);
case 2:
printf("enter radius of circle");
scanf("%d",&r);
area=3.142*r*r;
printf("area of circle=%d",area);
case 3:
printf("enter base and height");
scanf("%d %d",&b,&h);
area=0.5*b*h;
scanf("area of traingle=%d",area);
case 4:
print("enter length of square");
scanf("%d",&l);
area=l*l;
printf("area of square=%d",area);
}
getch();
   }