Question

Three towns A, B, C are situated such that /AB/=25km and /AC/=30km. The bearing of B from A is 56°and bearing of C from A is 282°. Calculate the bearing of B from C

Answer 1

$360°-282°=78°$

$78°+56°=134°$

$BC=\sqrt{25^2+30^2-2\cdot25\cdot30\cdot\cos134°}=50.7\ (km)$

$\cos\gamma=\frac{30^2+50.7^2-25^2}{2\cdot30\cdot50.7}=0.9354\to\gamma=20.7°$

$\theta=180°-78°-20.7°=81.3°$ . Answer