Untitled

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    float a;
    printf("pls enter the edge of the square:");
    scanf("%f", &a);
    if (a<=0){
        printf(" the edge must be a positive number!");

    } else {
     printf(" the perimeter of the square is %f\n", a*4);
     printf(" the are of the square is %f\n", a*a);
    }
    return 0;
}