Measuring Angles

Estimate the size of these angles and decide whether they

are:

A

B

C

66˚

Acute

Reflex

Obtuse

290˚

107˚

Acute?

Obtuse?

Reflex?

Angle <90˚

Angle >180˚

90˚ < Angle <180˚

Bearings

You need to know that the bearing of a point A from an observer O is the

angle between the line OA and the North line through O,

measured in a clockwise direction.

A

N

N

O

30°

210°

Clockwise – the direction that

the hands move on a clock

In the diagram the bearing of A from O is 210º. The three-figure bearing of O from A is 030º.

Bearings Continued

A ship travels on a bearing of 120º for 100 sea miles, then on a

bearing of 230º for a further 200 sea miles. Represent this

with a scale drawing. What is the ship's distance and bearing

from the starting point?

120º

100 sea miles

230º

200 sea miles

Start

Finish

Estimate the distance first.

Is it bigger than 100 sm?

Is it less than 200 sm?

North

2003-10-16T09:16:29