C Program to Calculate Area of Circle using Pointer?

Answer 1

#include<stdio.h>

void func(int r, float *a, float *p )
{
    *a = 3.14 * r * r ;
    *p = 2 * 3.14 * r ;
}

void main( )
{
   int radius ;
   float area, perimeter ;
clrscr();
   printf ( "nEnter radius of a circle " ) ;
   scanf ( "%d", &radius ) ;

   func( radius, &area, &perimeter ) ;

   printf ( "Area = %f", area ) ;
   printf ( "nPerimeter = %f", perimeter ) ;
}

Output

Enter radius of a circle 5
Area = 78.500000
Perimeter = 31.400000