Bearings Flashcards

All 6 cards in this deck

What are the three rules for writing a bearing?

Measured from north, clockwise, and written with three figures.
e.g. $25^\circ$ is written $025^\circ$

How do you find the back bearing (the bearing of A from B) when the bearing of B from A is less than $180^\circ$?

e.g. bearing of B from A is $147^\circ$

Add $180^\circ$.
$147 + 180 = 327^\circ$

How do you find the back bearing when the given bearing is more than $180^\circ$?

e.g. bearing of B from A is $250^\circ$

Subtract $180^\circ$.
$250 - 180 = 070^\circ$

True or false? The bearing of A from B is the same as the bearing of B from A.

False. They differ by $180^\circ$ (a back bearing).

Why are the north lines at two different points on a diagram useful when working out a bearing?

They are parallel, so alternate/co-interior angle facts link the two bearings.

What are the steps to mark a point from a given bearing and distance?

e.g. R is 55 km from T on a bearing of $065^\circ$, scale 1 cm to 10 km

1. Convert the distance with the scale: $55 \div 10 = 5.5$ cm
2. Draw a north line at T and measure $065^\circ$ clockwise from it
3. Measure 5.5 cm along that direction and mark R with a cross