write a program to find radius of incircle of equilateral triangle of given side.

#include<stdio.h>
main()
{
float a,rad_of_incircle;
printf("enter the side of equilateral triangle:");
scanf("%f",&a);
rad_of_incircle=a/(2*1.73);
printf("radius of incircle of an equilateral triangle of side a:%f",rad_of_incircle);
}