Prog#251: area of circle

C Programming
#1 
/*
area of circle
Program#251
*/
#include<stdio.h>
main()
{
int r;
float c;
scanf("%d", &r);
c=area(r);
printf("%f", c);
}
area(x)
int x;
{
float z;
z=3.14*x*x;
return z;
}