If the whole circle bearing of a line is 170°12', then its reduced bearing is:

A child walks on a level surface from point P to point Q at a bearing of 30°, from point Q to point R at a bearing of 90°, and then directly returns to the starting point P at a bearing of 240°. The straight-line paths PQ and QR are 4 m each. Assuming that all bearings are measured from the magnetic north in degrees, the straight-line path length RP (in meters) rounded off to the nearest integer is:

In chain surveying on sloping ground, if 'h' is the difference in level between two points and 'l' is the length of the slope, then the horizontal distance 'D' is given by which formula?