Bearings Flashcards

All 6 cards in this deck

What is a bearing?

An angle measured from the north line, clockwise, written with three figures.
e.g. $072°$

What are the steps to measure a bearing from a diagram with a protractor?
e.g. measure the bearing of $B$ from $A$

1. Draw a north line at the point you measure from ($A$).
2. Put the protractor centre on $A$ with $0°$ on the north line.
3. Measure clockwise to the line $AB$ and write it with three figures, e.g. $072°$.

How do you find the back bearing (the bearing of $A$ from $B$) when you know the bearing of $B$ from $A$?
e.g. the bearing of $B$ from $A$ is $147°$

Add $180°$ if the bearing is less than $180°$, subtract $180°$ if it is $180°$ or more.
$147 + 180 = 327°$

The north lines drawn at two different points are parallel. What angle fact does this give you when working with bearings?

Co-interior (allied) angles between the two north lines and the line joining the points add up to $180°$.

True or false? The bearing of $A$ from $B$ is measured from a north line drawn at $B$.

True. You always measure from the north line at the point you are travelling from.

True or false? The bearing of $A$ from $B$ is always $180°$ more than the bearing of $B$ from $A$.

False. You add $180°$ only if the first bearing is under $180°$; otherwise you subtract $180°$, so the answer stays between $0°$ and $360°$.