Думаю, что нужно так...
#include
void flush(void) {
while (getchar() != '\n');
}
typedef struct {
char gender;
int age;
float height;
char name[20];
} person;
int main(void) {
person p;
printf("Name: ");
scanf("%s", p.name);
printf("Age: ");
scanf("%i", &p.age);
flush();
printf("Gender m/f: ");
p.gender = getchar();
flush();
printf("Height: ");
scanf("%f", &p.height);
printf("Name: %s, %i years old, %.2f m.", p.name, p.age, p.height);
if (p.gender == 'm') printf(" %s", "You are a man");
if (p.gender == 'f') printf(" %s", "You are a woman");
puts("");
return 0;
}