The whole circle bearing 338° 42’ converted into quadrant form is given as
- AN 21° 18’ WCorrect
- BS 21° 18’ E
- CW 21° 18’ N
- DN 31° 18’ W
Solution
Concept
Conversion of WCB to quadrantal bearing
Formula
For 270° < WCB < 360°: QB = N (360° − WCB) W
Step-by-step solution
1. WCB = 338° 42′ lies in the fourth quadrant (270°–360°). 2. Reduced bearing = 360° − 338° 42′ = 21° 18′. 3. Quadrantal bearing = N 21° 18′ W.
Explanation
In the fourth quadrant the bearing is measured from north towards west, so QB = N (360° − WCB) W = N 21° 18′ W.
Shortcut
4th quadrant: N (360 − WCB) W; 3rd: S (WCB − 180) W; 2nd: S (180 − WCB) E.
Common mistake
Subtracting 338° 42′ from 360° incorrectly as 31° 18′.
Correct answer: A) N 21° 18’ W