#include <stdio.h>
#define PI 3.14159
int main(void)
{
float area , circumference , radius;
printf(<q>What is the radius of the circle.\n</q>);
scanf(<q>%f</q>,&radius);
area = PI * radius * radius;
circumference = 2.0 * PI * radius;
printf(<q>The circumference of the circle is %1.2f.\n</q>,circumference);
printf(<q>The area of the circle is %1.2f.\n</q>,area);
return 0;
}

Output:
What is the radius of the circle 4
The circumference of the circle is 25.12