#include <stdio.h>
#include <math.h>
int main() {
int rc; // used to check return codes of scanf
float radius, height;
printf("Enter radius: ");
rc = scanf("%f", &radius);
// scanf returns number of scanned items. If input is invalid then 0 values will have been scanned.
if (rc != 1) {
printf("Please enter an positive real integer or decimal\n");
return 1;
}
printf("Enter height: ");
rc = scanf("%f", &height);
printf("Surface area: %f\n", 2*M_PI*radius*radius + 2*M_PI*radius*height);