Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: First Term
Week: 11
Age: 15 years
Duration: 45 minutes
Subject: Technical Drawing
Curriculum Theme: Technical Drawing
Previous Lesson: Quadrilaterals: Definition, Types and Properties.
Topic: QUADRILATERALS
Subject Matter: construction of square, construction of rectangle, construction of kite, construction of parallelogram, use of compass, tee square and straight edge for accurate construction

Specific Objectives

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

Cognitive Domain:

Define a quadrilateral.
Identify different types of quadrilaterals.
State the basic properties of a square, rectangle, kite, and parallelogram.

Affective Domain:

Appreciate the importance of accuracy in technical drawing.
Participate actively in class discussions and construction activities.
Show interest in drawing various geometric shapes.

Psychomotor Domain:

Construct a square accurately using drawing instruments.
Construct a rectangle accurately using drawing instruments.
Construct a kite accurately using drawing instruments.
Construct a parallelogram accurately using drawing instruments.

Collaborate with peers during practical construction sessions.
Share drawing instruments responsibly.

Reference Materials

The following resources were used in planning this lesson:

Nigerian Educational Research and Development Council (NERDC) Senior Secondary Education Curriculum for Technical Drawing.
State Unified Scheme of Work for Technical Drawing SSS 1.
A.B. Arinze (2010). Technical Drawing for Senior Secondary Schools. Evans Brothers (Nigeria Publishers) Limited.
Online resources for geometric constructions.

Instructional Materials

The teacher will teach this lesson with the aid of:

Pair of compasses
Tee square
Drawing board
Straight edge/Ruler
Pencils (HB, 2H)
Eraser
Drawing paper
Models of different quadrilaterals
Charts and posters illustrating construction steps

Rationale for the Lesson

This lesson helps pupils understand the fundamental geometric shapes that are common in engineering, architecture, and everyday objects. Learning to construct quadrilaterals accurately provides pupils with essential skills for technical drawing and various design applications in their future studies and careers.

Prerequisite/Previous Knowledge

Pupils are expected to have basic knowledge of plane shapes, angles, lines, and the use of basic drawing instruments like rulers, pencils, and set squares.

Lesson Content/Board Summary

QUADRILATERALS

Definition of a Quadrilateral

A quadrilateral is a polygon with four sides and four angles. The sum of the interior angles of any quadrilateral is 360 degrees.

Types of Quadrilaterals and their Properties

The following are common types of quadrilaterals:

Square: A quadrilateral with four equal sides and four right angles (90 degrees). Its diagonals are equal and bisect each other at right angles.
Rectangle: A quadrilateral with opposite sides equal and parallel, and four right angles. Its diagonals are equal and bisect each other.
Kite: A quadrilateral with two pairs of equal-length sides that are adjacent to each other. Its diagonals are perpendicular, and one diagonal bisects the other.
Parallelogram: A quadrilateral with opposite sides parallel and equal in length. Opposite angles are equal, and consecutive angles are supplementary (add up to 180 degrees). Its diagonals bisect each other.

Construction of a Square (given side length)

To construct a square with a given side length, L:

Draw a horizontal line segment AB of length L.
At point A, construct a perpendicular line segment AX.
Measure length L along AX from A to mark point D.
With D as centre and radius L, draw an arc.
With B as centre and radius L, draw another arc to intersect the first arc at point C.
Join C to D and C to B to complete the square ABCD.

Construction of a Rectangle (given side lengths)

To construct a rectangle with given length L and breadth B:

Draw a horizontal line segment AB of length L.
At point A, construct a perpendicular line segment AX.
Measure length B along AX from A to mark point D.
At point B, construct a perpendicular line segment BY.
Measure length B along BY from B to mark point C.
Join C to D to complete the rectangle ABCD.

Construction of a Kite (given diagonals and one side)

To construct a kite given the lengths of its diagonals and one side:

Draw the longer diagonal AC.
Bisect AC to find its midpoint, say M.
Draw a perpendicular line through M.
Mark points B and D on this perpendicular line such that MB + MD equals the shorter diagonal. Also ensure the given side length condition is met.
Join A to B, B to C, C to D, and D to A to form the kite ABCD.

Construction of a Parallelogram (given two adjacent sides and an included angle)

To construct a parallelogram with adjacent sides AB and AD and included angle A:

Draw line segment AB.
At point A, construct the given angle A with AB.
Along the arm of the angle, mark point D such that AD is the given length.
With B as centre and radius equal to AD, draw an arc.
With D as centre and radius equal to AB, draw an arc to intersect the first arc at point C.
Join B to C and D to C to complete the parallelogram ABCD.

Importance of Accurate Construction

Accurate construction is important in technical drawing for the following reasons:

It ensures that designs and plans are precise and can be correctly interpreted and implemented.
It prevents errors in manufacturing and construction, saving time and resources.
It develops neatness and attention to detail, which are essential skills in technical fields.
It allows for proper visualization and analysis of geometric properties.

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 reviews the previous lesson briefly. The teacher then asks pupils to identify common objects in the classroom that have four sides, such as the board, door, or window. This leads to the introduction of quadrilaterals.
Pupils’ Activity: Pupils respond to questions and identify objects, linking them to the concept of four-sided shapes.
Learning Point: Pupils recall previous knowledge and are prepared for the new topic.

Step 2: Definition and Types of Quadrilaterals

Time: 8 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher defines a quadrilateral, explaining its properties (four sides, four angles, sum of angles is 360 degrees). The teacher then introduces different types of quadrilaterals using charts and models, explaining the unique properties of each (square, rectangle, kite, parallelogram).
Pupils’ Activity: Pupils listen attentively, observe the charts and models, and take notes. They may ask questions for clarification.
Learning Point: Pupils understand the definition and various types of quadrilaterals with their specific properties.

Step 3: Demonstration of Square and Rectangle Construction

Time: 10 minutes
Teaching Skill: Demonstration/Modelling
Teacher’s Activity: The teacher demonstrates, step-by-step, the accurate construction of a square and a rectangle on the drawing board using the tee square, compass, and straight edge. The teacher emphasizes the importance of precision and proper use of instruments.
Pupils’ Activity: Pupils observe the teacher’s demonstration carefully, noting the steps and techniques used for accurate construction.
Learning Point: Pupils learn the practical steps for constructing a square and a rectangle accurately.

Step 4: Demonstration of Kite and Parallelogram Construction

Time: 10 minutes
Teaching Skill: Demonstration/Modelling
Teacher’s Activity: The teacher continues the demonstration, showing the step-by-step construction of a kite and a parallelogram on the drawing board. The teacher highlights the differences in construction methods for each shape and reinforces the need for accuracy.
Pupils’ Activity: Pupils pay close attention to the demonstration, asking questions about specific steps if needed.
Learning Point: Pupils learn the practical steps for constructing a kite and a parallelogram accurately.

Step 5: Practical Construction Practice

Time: 7 minutes
Teaching Skill: Guided Practice
Teacher’s Activity: The teacher guides pupils to individually practice constructing one or more of the quadrilaterals demonstrated. The teacher moves around the classroom, providing assistance and correcting errors.
Pupils’ Activity: Pupils attempt to construct a square, rectangle, kite, or parallelogram on their drawing paper using their instruments.
Learning Point: Pupils develop practical skills in constructing quadrilaterals and receive immediate feedback.

Step 6: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define a quadrilateral.
Mention two types of quadrilaterals.
State one property of a square.
Explain why accuracy is important in technical drawing construction.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 7: Conclusion

Time: 5 minutes
Teaching Skill: Summarization/Assignment
Teacher’s Activity: The teacher summarizes the key points of the lesson, reiterating the definition of quadrilaterals, their types, and the importance of accurate construction. The teacher assigns homework, asking pupils to practice constructing all four types of quadrilaterals at home.
Pupils’ Activity: Pupils listen to the summary and copy down the homework assignment.
Learning Point: Pupils consolidate their learning and are given tasks to reinforce their skills.

Lesson Keywords

Quadrilateral – A polygon with four sides and four angles.
Square – A quadrilateral with four equal sides and four right angles.
Rectangle – A quadrilateral with opposite sides equal and four right angles.
Kite – A quadrilateral with two pairs of equal-length adjacent sides.
Parallelogram – A quadrilateral with opposite sides parallel and equal in length.

Differentiation

For pupils who grasp the concepts quickly, the teacher can provide more complex construction challenges, such as constructing a rhombus or a trapezoid, or quadrilaterals with given diagonals. For pupils who require more support, the teacher will provide one-on-one guidance during practical sessions and simplified step-by-step handouts for reference.

Note for teachers using this lesson plan

Ensure all pupils have the necessary drawing instruments before the lesson begins. Emphasize the correct handling and use of instruments to promote good drawing habits. Encourage neatness and precision throughout the construction exercises. Provide ample practice time for pupils to develop their skills.