Class: Junior Secondary School 3 (JSS 3 / JS3)
Term: Third Term
Week: 7
Age: 14 years
Duration: 45 minutes
Subject: Basic Science and Technology
Curriculum Theme: Basic Science
Previous Lesson: Processing of Ceramics and Glass: Methods of Ceramics and Glass.
Topic: Drawing Practices
Subject Matter: Pictorial Drawing and Oblique Drawing, Isometric drawing, Definition and Types: Construction of simple objects

Specific Objectives

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

Cognitive Domain:

Define pictorial drawing.
Distinguish between oblique drawing and isometric drawing.
State the characteristics of isometric and oblique drawings.

Affective Domain:

Appreciate the importance of pictorial drawings in conveying design ideas.
Show interest in learning different types of technical drawings.

Psychomotor Domain:

Construct a simple object using oblique drawing.
Construct a simple object using isometric drawing.

Collaborate with peers in discussing and identifying different drawing types.
Share drawing tools and materials responsibly.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum
State Unified Scheme of Work
Basic Science and Technology for Junior Secondary Schools Book 3
https://www.youtube.com/watch?v=k_n79_yqN-I
https://www.youtube.com/watch?v=F070XW6F5p4

Instructional Materials

The teacher will teach this lesson with the aid of:

Drawing board
T-square
Set squares (30/60 degrees and 45 degrees)
Pencils (HB, 2H)
Eraser
Drawing paper
Models of simple geometric objects (e.g., cube, rectangular prism, cylinder)
Chart showing examples of oblique and isometric drawings.

Rationale for the Lesson

This lesson helps pupils understand how to represent three-dimensional objects on a two-dimensional surface. This skill is important for communicating design ideas clearly and is foundational for various technical fields and artistic endeavors.

Prerequisite/Previous Knowledge

Pupils are expected to have a basic understanding of two-dimensional shapes, measurement, and the use of basic drawing instruments.

Lesson Content/Board Summary

Drawing Practices: Pictorial Drawing

Definition of Pictorial Drawing

Pictorial drawing is a type of drawing that shows an object as it would appear to the eye, giving a three-dimensional view on a two-dimensional surface. It helps to visualize the object’s length, width, and height.

Types of Pictorial Drawing

The main types of pictorial drawing include:

Oblique Drawing
Isometric Drawing
Perspective Drawing

Oblique Drawing

Oblique drawing is a method of pictorial drawing where one face of the object is drawn true size and shape, parallel to the plane of projection. The receding lines (depth lines) are drawn at an angle (usually 30°, 45°, or 60°) to the horizontal.

Characteristics of Oblique Drawing:

One face (front view) is shown in true shape and size.
Receding lines are parallel to each other.
Depth can be drawn at full size (Cavalier Oblique) or half size (Cabinet Oblique) to prevent distortion.

Construction of Simple Objects using Oblique Drawing:

To draw a simple object (e.g., a rectangular block) in oblique:

Step 1: Draw the front face of the object in its true shape and size.
Step 2: From each corner of the front face, draw parallel receding lines at the chosen angle (e.g., 45°) and desired length (full or half depth).
Step 3: Connect the ends of the receding lines to form the back face of the object.
Step 4: Erase any hidden lines or make them dashed if required.

Isometric Drawing

Isometric drawing is a method of pictorial drawing where all three principal axes (length, width, height) are equally inclined to the plane of projection. The axes are typically drawn at 30° to the horizontal, with the vertical axis remaining vertical.

Characteristics of Isometric Drawing:

All three main axes (length, width, height) are shown equally foreshortened (though often drawn true to size for simplicity in school).
The angles between the isometric axes are 120°.
Lines parallel to the isometric axes are called isometric lines and are drawn to scale.
Non-isometric lines (lines not parallel to the axes) are not drawn to scale.

Construction of Simple Objects using Isometric Drawing:

To draw a simple object (e.g., a cube) in isometric:

Step 1: Draw a vertical line (representing height).
Step 2: From the bottom of the vertical line, draw two lines at 30° to the horizontal, one to the left and one to the right (representing length and width).
Step 3: Measure the dimensions of the object along these three axes.
Step 4: From the ends of these measured lines, draw parallel lines to complete the isometric box or shape.
Step 5: Erase excess lines and darken the visible outlines of the object.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to identify objects around the classroom. The teacher then asks how these 3D objects can be represented on a flat piece of paper.
Pupils’ Activity: Pupils respond by identifying objects and suggesting ways to draw them, leading to a discussion on showing depth.
Learning Point: Pupils are introduced to the concept of representing 3D objects in 2D and connect to previous knowledge.

Step 2: Explanation of Pictorial Drawing

Time: 7 minutes
Teaching Skill: Explanation/Lecture
Teacher’s Activity: The teacher defines pictorial drawing, explaining its purpose and introducing its main types: oblique and isometric drawing. The teacher uses charts to show examples.
Pupils’ Activity: Pupils listen attentively, observe the charts, and ask clarifying questions about pictorial drawing.
Learning Point: Pupils understand the definition and general types of pictorial drawing.

Step 3: Explanation of Oblique Drawing

Time: 7 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher explains oblique drawing, its characteristics, and demonstrates how to draw a simple rectangular block in oblique using a drawing board and set squares.
Pupils’ Activity: Pupils observe the demonstration, take notes, and identify the key features of oblique drawing.
Learning Point: Pupils grasp the concept and basic construction method of oblique drawing.

Step 4: Explanation of Isometric Drawing

Time: 7 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher explains isometric drawing, its characteristics, and demonstrates how to draw a simple cube in isometric using a drawing board and 30/60 degree set square.
Pupils’ Activity: Pupils pay close attention to the demonstration, note the differences from oblique drawing, and try to visualize the process.
Learning Point: Pupils understand the concept and basic construction method of isometric drawing.

Step 5: Types and Construction of Simple Objects

Time: 7 minutes
Teaching Skill: Guided Practice
Teacher’s Activity: The teacher further explains the types of oblique (Cavalier and Cabinet) and reinforces the construction steps for simple objects in both oblique and isometric views, referring to the board summary.
Pupils’ Activity: Pupils actively participate in discussion, ask questions about the construction steps, and review their notes.
Learning Point: Pupils consolidate their understanding of the types and construction principles.

Step 6: Practical Application/Guided Practice

Time: 7 minutes
Teaching Skill: Practical Application
Teacher’s Activity: The teacher provides a simple model (e.g., a small rectangular prism) and guides pupils to attempt drawing it in either oblique or isometric view on their drawing paper, offering assistance as needed.
Pupils’ Activity: Pupils follow the teacher’s instructions, use their drawing instruments to attempt drawing the object, and seek help when encountering difficulties.
Learning Point: Pupils apply the learned drawing techniques to construct a simple object.

Step 7: Evaluation/Review

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

What is pictorial drawing?
State two types of pictorial drawing.
Explain the main difference between oblique drawing and isometric drawing.
Describe two characteristics of isometric drawing.

Pupils’ Activity: Pupils answer orally and in writing.
Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teacher’s Activity: The teacher summarizes the key points of the lesson, emphasizing the importance of pictorial drawings in technical communication. The teacher assigns homework for pupils to draw a simple object (e.g., a chair or table) in both oblique and isometric views.
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils recap the lesson and are given a task to reinforce learning.

Lesson Keywords

Pictorial Drawing – A drawing that shows an object as it appears to the eye in three dimensions.
Oblique Drawing – A pictorial drawing where one face is true size and depth lines are drawn at an angle.
Isometric Drawing – A pictorial drawing where three axes are equally inclined, typically at 30 degrees to the horizontal.
Cavalier Oblique – An oblique drawing where receding lines are drawn at full length.
Cabinet Oblique – An oblique drawing where receding lines are drawn at half length.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to draw more complex objects or explore perspective drawing. For pupils who need more support, the teacher will provide simplified models, more one-on-one guidance, and allow them to focus on mastering one type of pictorial drawing first.

Note for teachers using this lesson plan

Ensure that pupils have access to appropriate drawing instruments. Provide clear, step-by-step demonstrations and circulate to offer individual assistance during practical activities. Encourage pupils to practice regularly to improve their drawing skills. Emphasize neatness and accuracy in all drawings.