#include <stdio.h> int main() { const float PI = 3.141593; float diameter; float radius; float circ; float area; printf("Enter the diameter of a circle in millimeters:"); scanf("%f", &diameter); circ = PI * diameter; radius = diameter / 2; area = PI * (radius * radius); printf("\n\tCircumference is %.2f mm" , circ); printf("\n\tAnd the area is %.2f sq.mm\n" , area); return 0; }