tacheometry

tachemetry

telemetry

all the above.

when the instrument is being shifted, the staff must not be moved

when the staff is being carried forward, the instrument must remain stationary

both when the instrument is being shifted, the staff must not be moved and when the staff is being carried forward, the instrument must remain stationary

neither when the instrument is being shifted, the staff must not be moved nor when the staff is being carried forward, the instrument must remain stationary

2.828

3.828

1.828

0.828.

20°

30°

45°

60°

tangent of its reduced bearing

sign of its reduced bearing

cosine of its reduced bearing

cosecant of its reduced bearing.