Hey guys this is Eddie, welcome to another math tutorial today I want to
talk about bearings which which is a quite important part of maths because a
lot of navigation type questions will require you to understand bearings and
you also learn to use trigonometry with bearing type questions so there are two
different types of bearings that you could be given in a question the first
type is compass bearings compass bearings and the second type is true
bearing and to start off I will talk about compass bearing first so compass
bearings is based on the concept that we have a north east south and west okay so
every direction from the origin which is here every direction from the origin can
be defined using one of these using either the North or the South first so
for example starting from the origin let's say I want to travel in this
direction here now let's say I have measured this angle here to be 30
degrees then this direction from the origin is then called north 30 degrees
east so that's how you label this direction so where what I say that I'm
traveling at a bearing or at a compass bearing of North
30 degrees East that's the direction I'm traveling in so let's say I'm
traveling in this direction here oops hang on a second just trying to draw a
straight line let's say I'm traveling in this direction here and this angle here
is 40 degrees then the name that I give to this direction is called South 40
degrees West because the angle 40 degrees is created from the south
towards the west now what if I have an angle like this one and what if this
angle here is 20 degrees how should I name this this direction
well if this angle here is 20 degrees then this angle here must be 70 degrees
because the angle between north and west must be 90 degrees because it's a right
angle so this direction is then called North 70 degrees West so basically every
direction has to start with either north or south okay
last one so for example this direction here
this direction here let's say I have 15 degrees here so how big is this angle
must be 90 minus 15 which is 75 degrees
so this angle this direction is therefore called
South 75 degrees East all right every direction has to start with either north
or south and then the angle and then other east or west okay let's talk about
true bearing which is easier than compass bearing because everything is
measured from the north so let's say I have a person traveling this angle let's
say this is 70 degrees so the bearing of this direction will just be 070
degrees true
now what if they travel in this direction then we have to measure the
angle from the beginning so from the beginning here all the way around to
here so let's say if this angle alone on its own is 20 degrees from the North to
the South is 180
so this angle here will be 180 plus 20 which is 200 degrees true now what if we
have an angle like this and let's say this angle here is 30 degrees well the
direction will therefore be 360 which is the whole revolution from the North all
the way around to the North again minus 30 which will be 330 degrees okay thanks
for watching the bearings tutorial hopefully you have a better
understanding of bearings after watching this see you next time.