C

<01.05>

/* The "circle" program (from keyboard) */ #include <stdio.h> #define PI 3.1416 int main (void) { /* declarations */ double diam, area, circ, r; /* get diameter from user */ printf ("Enter a value for the diameter: "); scanf ("%lf", &diam); /* do the computations */ r = diam / 2; area = PI * r * r; circ = 2 * PI * r; /* display the report on the screen */ printf ("\nA circle with a diameter of %3.1lf cm, ", diam); printf ("has an area of %5.3lf cm2\n", area); printf ("and a circumference of %4.2lf cm.\n", circ); return (0); }

Enter a value for the diameter: 10 A circle with a diameter of 10.0 cm, has an area of 78.540 cm2 and a circumference of 31.42 cm.