Bearings

There are four main directions on a compass; north, south, east and west.

Compass

A compass can be used to describe a direction. Another method of describing directions is using bearings.

Ships use bearings to navigate. A bearing is measured in degrees.

curriculum-key-fact
A bearing:
  • is measured from the north line
  • is measured clockwise
  • has three figures
For example, the bearing for the direction of east is 090°.

Example

This plane is flying at an angle of 48° from North. The bearing it flies at is 048°.

Flight path creating angle of 45degrees from North

This plane is flying at an angle of 20° anticlockwise from North. Since a bearing is measured clockwise, the bearing it flies at is 360 - 20 = 340°.

Flight path creating angle of 20degrees from North
Question

Measure the bearing of the shark from the ship.

Shark and ship

Method 1

Draw a line between the ship and the shark. Draw a line pointing North from the ship.

Line between shark and ship, with vertical line labelled N, coming out of the ship

The shark is more than 180° clockwise from North. Place the centre of the protractor on the ship and 180° facing North.

Protractor laid on the two lines that are drawn. Angle of 80 degrees north

Measure the angle clockwise from 0° to the line between the ship and the shark. In this case the measurement is 100°.

A bearing is measured from North. Add the angle to 180°:

180 + 100 = 280

The bearing of the shark from the ship is 280°.

Method 2

Draw a line between the ship and the shark. Draw a line pointing north from the ship.

Line between shark and ship, with vertical line labelled N, coming out of the ship

The shark is more than 180° from North. Place the centre of a protractor on the ship and 0° facing North.

Protractor laid on the two lines that are drawn. Angle of 100 degrees south

Measure the angle anticlockwise from 0° to the line between the ship and the shark. In this case the measurement is 80°.

A bearing is measured clockwise from North. Subtract this angle from 360°.

360 - 80 = 280

The bearing of the shark from the ship is 280°.