In Mathematics, the study of bearings enables us to tell the position of objects with reference to one another.
Two important things about bearing:
• Angle (in degree), measured clockwise from the north direction.
• Must always be stated in three digits. with \(000^\circ\leq\theta<360^\circ\)
Let’s look at the diagram below.
Find the bearing of \(B\) from \(A\). 
The bearing of \(B\) from \(A\) is \(035{}^\circ\). | Find the bearing of \(A\) from \(B\). 
The bearing of \(A\) from \(B\) is \(215{}^\circ\). |
|
Bearing of \(A\) from \(B\) is not the same as the bearing of \(B\) from \(A\).
The following are \(3\) angle properties involving straight line:
• Alternate angle
• Corresponding angle
• Interior angle
are used quite often to find the bearings.
Know the directions
Problem involving Bearings
May involve the use of Sine Rule
• Sine Rule
\(\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}\) used when there are two given sides and one non-included angle, or when they are two given angles and one given side.
• Cosine Rule
\(c^2 = a^2 + b^2 - 2ab \cos C\) used when there are two given sides and one included angle, or when all three sides are given.