Write a C program to find the area and circumference of a circle

#include
int main()
{
int rad;
float PI=3.14,area,ci;

printf("nEnter radius of circle: ");
scanf("%d",&rad);

area = PI * rad * rad;
printf("nArea of circle : %f ",area);

ci = 2 * PI * rad;
printf("nCircumference : %f ",ci);

return(0);
}

Output:
Enter radius of a circle : 1
Area of circle : 3.14
Circumference  : 6.28