חייב עזרה בc#

[Reality]

#include <stdio.h>
#include <conio.h>

void main(void)
{
float a,b,c,d;
printf("Enter value of angle\n");
scanf("%f",&a);
getch();
if(a==90)
{
printf("The angle is straight\n");
getch();
}
else
if(a<90)
{
printf("The angle is sharp\n");
getch();
}
else
if(a>90)
{
printf("The angle is dim\n");
getch();
}
getch();
}