In a land survey of a coastal area the reduced level of the top of a cliff needs to be found as part of works to stabilise the cliff face. A baseline 35 m was set up on the foreshore area and the...

In a land survey of a coastal area the reduced level of the top of a cliff needs to be found as part of works to stabilise the cliff face. A baseline 35 m was set up on the foreshore area and the angles of inclination at the ends of the baseline were measured as shown in Figure. Also, with the theodolite telescope set horizontally at 0°, the heights of collimation of the instrument were found relative to the TBM, which are also shown in the diagram. (Hint: Use right-angle trigonometry and Pythagoras’ rule to help find the vertical height of point C above point A.) Consider errors in angular measurement.