#### Transcript Bearings

```Triangle
Trigonometry
Content
0 Introduction
0 What are bearings?
0 Application in Triangle Trigonometry
0 Application in Real Life
0 Sample Questions
0 Activity (Try it yourself!)
Introduction
0 What are bearings?
0 From Wikipedia,
0 A bearing is the angle between a line connecting two
points and a north-south line.
Key concepts
0 Just a quick revision of the three functions
0 Sine function (sin), defined as the ratio of the side
opposite the angle to the hypotenuse.
0 Cosine function (cos), defined as the ratio of the
0 Tangent function (tan), defined as the ratio of the
opposite leg to the adjacent leg.
Application in Triangle
Trigonometry
0 To cut a long story short, a bearing is the direction
from one object to another. In air navigation, bearings
are given as angles rotated clockwise from the north.
Application in Triangle
Trigonometry
0 A ship travels on a N50° E course. The ship travels
until it is due north of a port which is 10 nautical miles
due east of the port from which the ship originated.
How far did the ship travel?
0 The angle opposite d is the complement of 50°,
which is 40°. Therefore we can find d using the
Cosine Function
0 Cos40=a/h=10/d
0 D(cos)40=10
0 D=10/cos40=13.05 approx.
Application in Real Life
0 In Real Life, bearings are commonly used in three
0 With the help of bearings, soldiers, divers and hikers
alike will not get lost while exploring unknown or
new territory!
Application in Real Life
0 According to the US Army, bearings can also be used
in war-time conditions.
0 Bearings are able to:
0 Determine the location of a foreign object or target
0 Aid piloting of an aircraft
0 Bring a drone from one position to another by remote
0 Search and Rescue a lost soldier
Other Sample Questions
0 http://www.digitaldesk.org/resources/mathsweb/be
aring1.htm
use of bearings and how bearings work.
0 Bearings 1 through Bearings 3 are sample questions.
Sample Questions
0 http://www.mathsteacher.com.au/year7/ch08_angles
/07_bear/bearing.htm
0 This link uses some illustrations to explain the
concept of bearings as well as many examples
0 It covers bearings and directions
0 http://www.absorblearning.com/mathematics/demo
/units/KCA005.html#Directionanddistance