C Program to find area and circumference of a circle using pre processor directives

Program

#include<stdio.h>
#define PI 3.147
void main()
{
	float circumference;
	float radius;
	printf("Enter the radius of the Circle:\t");
	scanf("%f", &radius);
	circumference = 2 * PI * radius;
	printf("Circumference of the Circle:\t%f\n", circumference);
}

Output

Enter the radius of the Circle:	5
Circumference of the Circle:	31.469999