What are angles of elevation and depression, and true and compass bearings?
In this post, we solve practical problems involving Pythagoras’ theorem and the trigonometry of triangles, which may involve the ambiguous case, including finding and using angles of elevation and depression and the use of true bearings and compass bearings in navigation, as a part of the Prelim Maths Advanced course under the topic Trigonometric Functions and sub-part Trigonometry.
The angle of elevation is the angle formed between the horizontal and the specific line, above the horizontal, while the angle of depression is the angle formed between the horizontal and the specific line, below the horizontal. Compass bearings measure direction through the 4 main directions of North, South, East, West, while true bearings measure direction by measuring the angle in degrees from North.
What are true and compass bearings?
The following three videos cover true and compass bearings, going in-depth about what they are, and how to apply them in questions, also emphasising some crucial tips and tricks.
What are angles of elevation and depression?
The following video covers the definition of angles of elevation and depression, also going over some questions as examples.