TOPIC: ANGLES
A: TEACHING AND LEARNING MATERIALS
- Protractor.
- Ruler.
- Angle chart.
- Set square.
- Cardboard angle models.
- Chalkboard/whiteboard.
- Pupils’ exercise books and pencils.
B: REFERENCE MATERIALS
- Scheme of work.
- Recommended Mathematics textbook for Primary 5.
- Online educational resources.
C: PREVIOUS KNOWLEDGE
The pupils have seen corners in plane shapes and can identify right angles in squares and rectangles.
D: PERFORMANCE OBJECTIVES
By the end of the lesson, pupils should be able to:
- Explain an angle.
- Identify acute angles.
- Identify right angles.
- Identify obtuse angles.
- Identify straight angles.
- Measure simple angles with a protractor.
- Draw simple angles.
E: CONTENT
Meaning of an Angle
An angle is formed when two lines meet at a point.
Angles are measured in degrees (°).
Acute Angle
An acute angle is less than 90°.
Example:
45°
Right Angle
A right angle is exactly:
90°
It looks like the corner of a square.
Obtuse Angle
An obtuse angle is greater than 90° but less than 180°.
Example:
120°
Straight Angle
A straight angle is:
180°
Angles on a Straight Line
Angles on a straight line add up to:
180°
Example:
70° + 110° = 180°
Measuring Angles
A protractor is used to measure angles.
📐 Place the centre of the protractor on the point where the two lines meet.
F: LESSON PRESENTATION
F1: Teachers’ Activities
- Introduces angles using corners of objects.
- Explains acute, right and obtuse angles.
- Introduces straight angles.
- Demonstrates how to use a protractor.
- Draws simple angles.
- Gives pupils practical exercises.
F2: Pupils’ Activities
- Identify different angles.
- Compare angle sizes.
- Use a protractor.
- Measure simple angles.
- Draw given angles.
- Solve simple exercises.
G: CONCLUSION
The teacher revises the different types of angles and reminds pupils that angles are measured in degrees.
H: EVALUATION GUIDE
Pupils should be able to answer the following questions:
- What is an angle?
- What unit is used to measure angles?
- What type of angle is 45°?
- What type of angle is 90°?
- What type of angle is 120°?
- How many degrees are in a straight angle?
- What instrument is used to measure angles?