In order to determine the elevation (hB) of point B, a total station was set up at point A, and the zenith angle z and slope distance s were taken to a target at point B. The height of instrument was...

In order to determine the elevation (hB) of point B, a total station was set up at point A, and the zenith angle z and slope distance s were taken to a target at point B. The height of instrument was measured as hi, the height of target was measured as ht, and the elevation of point A is fixed as 30.00 m. Give the model for this problem in the form of x = f(l).