Question

The latitude and departure of a line AB are +78 m and -45.1 m, respectively. The whole circle bearing of the line AB is:

• A. ${150}^{\circ }$
• B. ${330}^{\circ }$
• C. ${30}^{\circ }$
• D. ${210}^{\circ }$

Answer 1

The correct option is B ${330}^{\circ }$

$Latitude=L\cos \theta =78$

$Departure=L\sin \theta =-45.1$

(-45.1, 78) Point lies in fourth quadrant

$\therefore \tan \varphi =\left(\frac{45.1}{78.0}\right)$

$\Rightarrow \varphi ={\tan }^{-1}\left(\frac{45.1}{78.0}\right)={30}^{\circ }$

The whole circle bearing of
$AB={360}^{\circ }-{30}^{\circ }={330}^{\circ }$