Lesson Note on Definitions, Types and Uses of Angles for JSS 2

Class: Junior Secondary School 2 (JSS 2)
Term: 1st Term
Week: 6
Age: 13 years
Duration: 45 minutes
Subject: Basic Science And Technology
Curriculum Theme: Basic Technology
Previous Lesson: Geometric Construction: Definition, Types, Uses, Bisection and Division of Lines
Topic: Angles (Part 1)
Subject Matter: Definitions, types and uses of angles.

Specific Objectives

By the end of the lesson, pupils should be able to:

• Cognitive Domain:
  (a) Define an angle.
  (b) Identify and describe different types of angles.
  (c) State uses of angles in real-life situations.
• Affective Domain:
  (a) Appreciate the importance of angles in construction, design, and daily life.
• Psychomotor Domain:
  (a) Demonstrate how to draw and measure angles using a protractor.
• Social Domain:
  (a) Work together in groups to identify examples of angles in their environment.

Reference Materials

The following resources was used in planning this lesson:

• 9 Years Basic Education Curriculum
• Lagos State Unified Scheme of work for Junior Secondary Schools
• BBC Bitesize – “Types of Angles” (https://www.bbc.co.uk/bitesize/topics/zb6tyrd/articles/zg68k7h )
• Relevant Textbooks

Instructional Materials

The teacher will teach this lesson with the aid of:

• Protractors and compasses
• Ruler and drawing instruments
• Charts showing types of angles
• Real objects (e.g. scissors, doors, books)
• Whiteboard and markers

Rationale for the Lesson

Understanding angles helps pupils build foundational geometry skills needed in mathematics, science, engineering, and daily life activities.

Prerequisite/Previous Knowledge

Pupils have prior knowledge of lines, shapes, and simple measurements, and can recognize basic geometric figures around them.

Lesson Content/Board Summary

Angles

Definition of Angles

An angle is formed when two straight lines meet at a point called the vertex. The size of an angle depends on how far one line turns from the other.

The following are key points about angles:

1. Angles are measured in degrees (°).
2. A protractor is used to measure the size of an angle.
3. The point where two lines meet is called the vertex, and the lines are called arms of the angle.

Types of Angles

Angles are classified based on their degree measurement.

The following are the types of angles:

1. Acute Angle – an angle less than 90°.
2. Right Angle – an angle equal to 90°.
3. Obtuse Angle – an angle greater than 90° but less than 180°.
4. Straight Angle – an angle equal to 180°.
5. Reflex Angle – an angle greater than 180° but less than 360°.
6. Complete Angle – an angle equal to 360°.

Uses of Angles

Angles are very useful in daily activities, science, and technology.

The following are the uses of angles:

1. In building and construction to ensure balance and design.
2. In road and bridge construction for safe bends and turns.
3. In drawing, painting, and arts for accurate designs.
4. In sports like football and basketball to determine direction of play.
5. In carpentry and metal works to create accurate joints.
6. In navigation and aviation to guide movement.

Teaching Methods/Instructional Techniques:

Lecture, Discussion, Demonstration, Explanation, Group Work, Question and Answer, Use of Visual Aids

Instructional Procedures

To deliver this lesson, the teacher will adopt the following steps:

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: Teacher shows pupils objects like scissors or doors and asks them what happens when the objects are opened or closed.
Pupils’ Activity: Pupils respond by describing the opening and closing movement.
Learning Point: Pupils are introduced to the idea of angles as turning or opening between lines.

Step 2: Definition of Angles

Time: 7 minutes
Teaching Skill: Explanation
Teacher’s Activity: Teacher defines an angle, explains vertex and arms, and shows how angles are measured with a protractor.
Pupils’ Activity: Pupils listen, observe the demonstration, and ask questions.
Learning Point: Pupils understand the meaning and basic features of angles.

Step 3: Types of Angles

Time: 12 minutes
Teaching Skill: Demonstration
Teacher’s Activity: Teacher explains the types of angles with drawings on the board and uses a protractor to measure examples.
Pupils’ Activity: Pupils identify types of angles and practice measuring them.
Learning Point: Pupils recognize and classify different types of angles.

Step 4: Uses of Angles

Time: 8 minutes
Teaching Skill: Discussion
Teacher’s Activity: Teacher discusses the uses of angles in real-life situations and provides practical examples.
Pupils’ Activity: Pupils mention where they have seen angles used in their environment.
Learning Point: Pupils understand the importance of angles in daily life.

Step 5: Note-Taking

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: Teacher dictates or writes the board summary for pupils to copy.
Pupils’ Activity: Pupils copy notes into their exercise books.
Learning Point: Pupils have a written record of key points of the lesson.

Step 6: Evaluation/Review

Time: 5 minutes
Teaching Skill: Questioning
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What is an angle?
2. List four types of angles.
3. State two uses of angles in real life.
   Pupils’ Activity: Pupils answer the questions orally.
   Learning Point: Pupils demonstrate understanding of lesson objectives.

Step 7: Conclusion

Time: 3 minutes
Teaching Skill: Reinforcement
Teacher’s Activity: Teacher summarizes the lesson and encourages pupils to practice measuring angles in their environment.
Pupils’ Activity: Pupils listen and ask questions.
Learning Point: Pupils consolidate their knowledge on angles.

Lesson Keywords

• Angle – space between two lines that meet at a point
• Vertex – the point where two lines meet to form an angle
• Arms – the lines that form an angle
• Protractor – an instrument used to measure angles
• Degrees – the unit for measuring the size of angles

Differentiation

Teacher simplifies explanations and uses real objects for struggling learners, while advanced learners practice drawing and measuring more complex angles.

Note for teachers using this lesson plan

Encourage pupils to relate angles to familiar objects in their environment. Always demonstrate with clear diagrams and supervise use of protractors carefully.