C- Read Radius of Circle, Calculate Area and Circumference

Write a c program to read radius of a circle and calculate area and circumference. The value of PI : 3.14159

C Code

#include <stdio.h>
#include <conio.h>
#include <math.h>
void main()
{
  float r, a, c;

  printf("nEnter radius of a circle:");
  scanf("%f",&r);

  a = M_PI*r*r;
  c = 2*M_PI*r;

  printf("nArea of cicle = %f",a);
  printf("nCircumference of circle = %f",c);

  getch();
}

Output