In surveying and air navigation, bearings are used to help identify the location of an object.
A three-figure bearing are:
Measured from north (\text{N})
Measured in a clockwise direction
Written using three figures
A \text{T} is often but not always used to indicate a true bearing. If the angle measure is less than 100\degree it would be written as 040\degree or 040\degree \text{T}.
To use true bearing to describe the location of a plane at point B from the airport at point A:
Place the centre of a compass on the starting point, in this case the airport.
Starting at North, rotate clockwise until we get to the line AB.
Write angle as the true bearing of point B.
Consider the point A.
Determine the true bearing of point A from O.
Consider the point A.
Find the true bearing of point A from O.
Find the true bearing of point A from point B.
True bearings are:
Measured from north (\text{N})
Measured in a clockwise direction
Written using three figures
Usually written with a \text{T} at the end
A compass bearing describes the location of a point using:
The starting direction of either north or south;
The acute angle needed to rotate
The direction to rotate, east or west.
The bearing needed or used completely depends on which position comes first. Have a look at the applet below. It quickly shows you how the angle changes depending on if we are measuring the bearing of A from B or B from A.
If A is between north and east, the compass bearing of A from B is measured clockwise from the north.
If A is between south and east, the compass bearing of A from B is measured anticlockwise from the south.
If A is between south and west, the compass bearing of A from B is measured clockwise from the south.
If A is between north and west, the compass bearing of A from B is measured anticlockwise from the north.
Consider the point A.
For the compass bearing of point A from O, which option shows the correct letters that should be written either side of the angle?
Complete the compass bearing of point A from O.
\text{N$\,⬚\,$E}