Writing pythagorean calculator to solve for b

Question

I cannot seem to get this to work. I don't know if it's syntax or a logic error on my part. It should take input of shooters distance and elevation and give true flat distance. B^2 = c^2-a^2. Also would like to input the angle theorem as well.
https://code.sololearn.com/c048bNR4bf2r/?ref=app

Answer 1

#include <math.h>

~~~

printf("\nPlease enter the observed distance to target and elevation above: ");
scanf("%f %f", &c, &a);