# Week 4 – Math 10 – Bearings and Angles of Elevations/Depression

It can be hard to solve problems using trigonometry if we don’t have a diagram to compare and look at. So when working to solve word problems knowing what bearings, the angle of elevation, and the angle of depression are helpful to create an illustration that will aid in the solving process.

What are bearings?

A bearing is an angle that is measured clockwise from the North direction. Planes and buses use bearings to determine a direction of travel based on their compass (as South from due North).

When solving many word problems, the angle of elevation or depression is determined by the eye level of the person and not from the ground. This is the line of sight, a sight line from the observer to some point of interest. To know what these angle mean, you also need to know what is something when it is vertical or horizontal.

Horizontal: is going side-to-side, for example, the horizon, a shadow, the ground

Vertical: is an up-down direction or position, for example upright, someone’s height, a tree, a building

The angle of elevation if the angle goes “upwards” from the line of sight. Therefore, the angle of depression is the “downwards” angle from the horizotal to a line of sight from the observer to some point of interest.