TOPIC 6: GEOMETRY
Points and Lines
The Concept of a Point
Explain the concept of a point
A​​ point​​ – is a smallest geometric figure which gives a position of object in a plane
A line segment – 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 – is a straight line joining two points in a plane
A line passing through two points e.g A and B and extends without end​​ (i.e infinitely)​​ 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 – is a measure of an amount of turn. For instance, a complete turn has an angle of 360º
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 40º 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