**TOPIC 6: GEOMETRY**

Points and Lines

The Concept of a Point

**Explain the concept of a point**

Aâ€‹â€‹Â pointâ€‹â€‹Â â€“ is a smallest geometric figure which gives a position of object in a plane

A line segment â€“ is a straight line joining two points in a plane

The Concept of a Point to Draw a Line

Extend the concept of a point to draw a line

A line segment â€“ is a straight line joining two points in a plane

A line passing through two points e.g A and B and extends without endâ€‹â€‹Â (i.e infinitely)â€‹â€‹Â in both directions is denoted by

The Difference Between a Line, a Line Segment and a Ray

Distinguish between a line, a line segment and a ray

A ray – is a line starting from a point, say A and pass through a point, say B and extends without end in one direction.It is denoted by

**Angles and Lines**

Angles

Draw angles

An angle â€“ is a measure of an amount of turn. For instance, a complete turn has an angle of 360Âº

Measuring Angles of Different Size Using a Protractor

Measure angles of different size using a protractor

There are several types of angles including:- acute, right, complementary, obtuse, supplementary and reflex angle

**Example 1**

Two angles are supplementary. One angle is three times the other. What are the angles?

Two angles are complementary. One angle is 40Âº greater than the other. What are the angles?

Solution

**Drawing Angles Using a Protractor**

Draw angles using a protractor

The angles formed by crossing lines includes vertically opposite angles, alternate angle and corresponding angles

Vertically opposite angles

The angles on the opposite sides of the crossing lines are equal