Question

If the quadrantal bearing of a line is N30°W, then the whole circle bearing of the line is

• A. 120°
• B. 210°
• C. 300°
• D. 330°

Hint:

To convert a quadrantal bearing to a whole circle bearing, subtract the quadrantal bearing from 360°.

Answer 1

The Correct Option is D

The quadrantal bearing of a line is given as N30°W, which means the line makes an angle of 30° with the north direction and is directed towards the west.

To convert this to the whole circle bearing (WCB), we use the following rule based on the quadrant:

• NθE: \( WCB = θ \)
• SθE: \( WCB = 180^\circ - θ \)
• SθW: \( WCB = 180^\circ + θ \)
• NθW: \( WCB = 360^\circ - θ \)

Since N30°W is in the Northwest quadrant, we apply the formula:

\[ {WCB} = 360^\circ - {30^\circ} = 330^\circ. \]

Hence, the whole circle bearing of the line is 330°, which corresponds to option (D).

The whole circle bearing is always measured clockwise from the north direction, making it a key concept in surveying.