WAP to illustrate the use of symbolic constants in a real-life application

//E Balagurusamy, Programming in ANSI C,4E
//Exercise 2.10, p51

//Note:
//. comments with //scaff indicate scaffolding code to help during development of code
//. can be safely commented out/removed (in production code)
#define PI 3.14159265
#include <stdio.h>
#include <conio.h>
int main(void)
{
    float radius=0.0, perimeter=0.0, area=0.0;
    printf("\nEnter the radius : ");

    scanf("%f", &radius);
    perimeter=2*PI*radius;
    area=PI*radius*radius;
    printf("\nPerimeter = %f", perimeter);
    printf("\nArea        = %f", area);
    getch();
    return 0;
}