Class: Junior Secondary School 2 (JSS2, JSS 2)
Term: 1st Term
Week: 5
Age: 13 years
Duration: 45 minutes
Subject: Basic Science And Technology
Curriculum Theme: Basic Technology
Previous Lesson: Ceramics, Rubber, and Plastics – Materials and Their Common Uses
Topic: Geometric Construction
Subject Matter: Lines: Definition of lines, Types and uses of lines, Bisection of lines, Division of lines

Specific Objectives

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

Cognitive Domain:
(a) Define and identify lines in geometric construction.
(b) Differentiate between various types of lines and state their uses.
(c) Explain the steps in bisection and division of lines.
Affective Domain:
(a) Appreciate the importance of accuracy and neatness in geometric construction.
(b) Show interest in applying lines correctly in technical drawings.
Psychomotor Domain:
(a) Use drawing instruments such as compass, ruler, and set square to bisect and divide lines.
Social Domain:
(a) Work in pairs or groups to practice line construction tasks and share feedback.

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
Math Open Reference – “Types of Lines in Geometry” (https://www.mathopenref.com/line.html)
Relevant Textbooks

Instructional Materials

The teacher will teach this lesson with the aid of:

Drawing instruments (compass, ruler, set square, pencil, protractor)
Chart showing different types of lines
Whiteboard and markers
Sample technical drawing sheets
Multimedia projection (if available)

Rationale for the Lesson

Understanding lines and their constructions equips pupils with foundational skills in technical drawing and design, which are essential in science, engineering, and technology.

Prerequisite/Previous Knowledge

Pupils have been introduced to basic geometric tools and can draw simple straight lines, angles, and circles using instruments.

Lesson Content/Board Summary

Geometric Construction

Definition of Lines

A line is a continuous mark that extends indefinitely in both directions without width or thickness. It is the foundation of all geometric drawings.

The following are the basic definitions:

A line has no beginning or end.
A line segment has two definite end points.
A ray has one fixed point and extends infinitely in one direction.

Types and Uses of Lines

Lines are classified based on their appearance and function in drawing.

These include:

Straight line – used for basic drawing and measurement.
Curved line – used to represent arcs and circles.
Horizontal line – drawn from left to right, used for base reference.
Vertical line – drawn from top to bottom, used to show height or upright positions.
Diagonal line – slanted line used to show slopes.
Perpendicular line – lines meeting at right angles.
Parallel lines – lines that never meet, used in technical drawings for accuracy.
Construction lines – faint lines used as guides in drawings.
Visible/outline – thick continuous lines that show the edges of objects.
Hidden lines – dashed lines that represent unseen parts of objects.

Bisection of Lines

Bisection means dividing a line into two equal parts using drawing instruments.

The following are the steps in bisecting a line:

Draw a straight line AB.
Place the compass at point A and draw an arc above and below the line.
Without changing the compass width, place it at point B and draw another arc above and below the line to intersect the first arcs.
Join the points of intersection with a straight line.
The new line cuts AB into two equal halves.

Division of Lines

Division of a line means splitting a line into a given number of equal parts.

The following are the steps in dividing a line:

Draw a straight line AB.
At point A, draw another line AC at any convenient angle.
Mark the required number of equal divisions on AC using a compass.
Connect the last point on AC to point B.
From each marked point on AC, draw parallel lines to AB using a set square.
The parallel lines divide AB into the required equal parts.

Teaching Methods/Instructional Techniques:

Discussion, Lecture, Explanation, Demonstration, Group Work, Question and Answer, Practical Illustration

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 reviews previous knowledge by asking pupils to draw simple lines using a ruler.
Pupils’ Activity: Pupils draw straight lines and recall basic geometric concepts.
Learning Point: Pupils are prepared to connect prior knowledge to new lesson content.

Step 2: Definition of Lines

Time: 7 minutes
Teaching Skill: Explanation
Teacher’s Activity: Teacher defines lines, line segment, and ray, then illustrates on the board.
Pupils’ Activity: Pupils observe, listen, and write notes.
Learning Point: Pupils understand the definition of lines.

Step 3: Types and Uses of Lines

Time: 10 minutes
Teaching Skill: Demonstration
Teacher’s Activity: Teacher presents charts of different lines, explains uses, and shows examples.
Pupils’ Activity: Pupils identify and state uses of lines.
Learning Point: Pupils learn different types of lines and their applications.

Step 4: Bisection and Division of Lines

Time: 15 minutes
Teaching Skill: Practical Demonstration
Teacher’s Activity: Teacher demonstrates step-by-step bisection and division of lines using compass, ruler, and set square.
Pupils’ Activity: Pupils practice the construction with their own instruments.
Learning Point: Pupils acquire skills in bisecting and dividing lines accurately.

Step 5: Note-Taking

Time: 3 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 permanent written record.

Step 6: Evaluation/Review

Time: 3 minutes
Teaching Skill: Questioning
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define a line and a line segment.
List four types of lines and state one use each.
State the steps in bisecting a line.
Explain how to divide a line into equal parts.
Pupils’ Activity: Pupils respond orally and practically.
Learning Point: Pupils show understanding of the lesson objectives.

Step 7: Conclusion

Time: 2 minutes
Teaching Skill: Reinforcement
Teacher’s Activity: Teacher summarizes the lesson and emphasizes the importance of accuracy in geometric construction.
Pupils’ Activity: Pupils listen and ask questions.
Learning Point: Pupils appreciate the role of lines in geometric construction.

Lesson Keywords

Line – a continuous mark without end points
Ray – a line with one fixed point extending endlessly
Parallel – lines that never meet
Bisect – to divide into two equal parts
Construction – process of making accurate drawings using instruments

Differentiation

Provide slower learners with guided steps and one-on-one support while advanced learners can attempt more complex line divisions. Group practice encourages peer learning.

Note for teachers using this lesson plan

Ensure pupils use sharp pencils and correct instrument handling. Move around the class to check accuracy of constructions. Encourage neatness and precision.