1. Use a protractor to measure the size of the following marked angles.

2. Draw the XY-axis on square paper and label positive X-axis as East, negative Y-axis South, negative X-axis West and positive Y-axis North. Now measure the following angles clockwise from the North.

What we understand from the activities is that one can usually measure an angle between two intersecting lines using compass. So if a fixed line and a point on the same plane is given, one can measure the angle from that fixed line to the line drawn from the fixed line to the given point.

In this section the fixed line is specified to be the north direction. We always measure from the north direction to the line joining the north direction to the given point in the clockwise direction.

In navigation, bearings are used to express something about direction. The three characteristics of bearings are:

• The basis of a bearing is at the north direction
• It always measures angle clockwise.
• It is written in three digit figures.