Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 2nd Term
Week: 1
Age: 15 years
Duration: 45 minutes
Subject: Technical Drawing
Curriculum Theme: Technical Drawing
Previous Lesson: .
Topic: Polygons: Definition, Types and Properties
Subject Matter: Definition of polygon, properties of polygons, regular polygons, irregular polygons, identification of triangle, pentagon, hexagon, and heptagon.

Specific Objectives

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

Cognitive Domain:

Define a polygon.
State at least three properties of polygons.
Differentiate between regular and irregular polygons.
Identify common polygons by their number of sides (e.g., triangle, pentagon, hexagon, heptagon).

Affective Domain:

Participate actively in class discussions about polygons.
Appreciate the importance of polygons in technical drawing and everyday objects.
Show interest in identifying different polygonal shapes.

Psychomotor Domain:

Sketch simple examples of regular and irregular polygons.
Use drawing materials to illustrate different polygons.

Collaborate with peers to identify and discuss polygon examples.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Technical Drawing.
State Unified Scheme of Work for Technical Drawing SSS 1.
Technical Drawing for Senior Secondary Schools by A.B. Salami.
https://waeconline.org.ng/e-learning/Technical-Drawing/TD103.pdf
https://www.scribd.com/document/500171630/Technical-Drawing-Jss1-3-Curriculum

Instructional Materials

The teacher will teach this lesson with the aid of:

Models of various polygons
Charts showing different types of polygons
Posters illustrating polygon properties
Drawing materials (ruler, pencil, compass, protractor)

Rationale for the Lesson

Understanding polygons helps pupils recognize shapes in their environment and provides a foundation for more complex technical drawing concepts. This knowledge is essential for accurately drawing and interpreting engineering designs and architectural plans.

Prerequisite/Previous Knowledge

Pupils are assumed to have basic knowledge of plane shapes such as squares, rectangles, and circles from their primary school mathematics.

Lesson Content/Board Summary

Polygons: Definition, Types and Properties

Definition of a Polygon

A polygon is a closed plane figure bounded by three or more straight lines (sides).

Properties of Polygons

The following are properties of polygons:

They are closed figures.
They have straight sides.
They are two-dimensional (plane) figures.
They have three or more sides.
The sum of interior angles depends on the number of sides.

Types of Polygons

Polygons are generally classified into two main types:

Regular Polygons: These are polygons where all sides are of equal length and all interior angles are equal. Examples include equilateral triangles, squares, and regular hexagons.
Irregular Polygons: These are polygons where sides are not all of equal length, and interior angles are not all equal.

Identification of Polygons by Number of Sides

Polygons are named based on the number of their sides. The following are common examples:

Triangle: A polygon with 3 sides.
Quadrilateral: A polygon with 4 sides.
Pentagon: A polygon with 5 sides.
Hexagon: A polygon with 6 sides.
Heptagon: A polygon with 7 sides.
Octagon: A polygon with 8 sides.
Nonagon: A polygon with 9 sides.
Decagon: A polygon with 10 sides.

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 name some shapes they see around them (e.g., door, window, book). The teacher then introduces the topic “Polygons” as a specific group of these shapes.
Pupils’ Activity: Pupils respond by naming various shapes and listen attentively to the introduction.
Learning Point: Pupils are introduced to the concept of polygons and relate it to everyday objects.

Step 2: Definition of a Polygon

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines a polygon as a closed plane figure bounded by three or more straight lines, using charts and models to illustrate.
Pupils’ Activity: Pupils listen, take notes, and ask questions for clarification.
Learning Point: Pupils understand the fundamental definition of a polygon.

Step 3: Properties of Polygons

Time: 7 minutes
Teaching Skill: Elaboration/Listing
Teacher’s Activity: The teacher explains the key properties of polygons, such as having straight sides, being closed, and being two-dimensional. The teacher uses examples on the board.
Pupils’ Activity: Pupils observe the examples, contribute to the discussion, and write down the properties.
Learning Point: Pupils identify and understand the characteristics that define a polygon.

Step 4: Types of Polygons (Regular and Irregular)

Time: 7 minutes
Teaching Skill: Differentiation/Categorization
Teacher’s Activity: The teacher differentiates between regular and irregular polygons, explaining that regular polygons have equal sides and equal angles, while irregular ones do not. The teacher shows examples using models and drawings.
Pupils’ Activity: Pupils observe the models and drawings, distinguish between regular and irregular polygons, and take notes.
Learning Point: Pupils can classify polygons into regular and irregular types.

Step 5: Identification of Polygons by Number of Sides

Time: 7 minutes
Teaching Skill: Naming/Identification
Teacher’s Activity: The teacher lists and identifies polygons such as triangles, pentagons, hexagons, and heptagons by their number of sides, using charts and examples. The teacher asks pupils to name polygons based on given sides.
Pupils’ Activity: Pupils identify polygons by their number of sides and participate in naming exercises.
Learning Point: Pupils can correctly name polygons based on the count of their sides.

Step 6: Class Activity/Practice

Time: 5 minutes
Teaching Skill: Practical Application
Teacher’s Activity: The teacher provides simple sketches of various polygons (regular and irregular) and asks pupils to identify them and state their properties. The teacher may also ask pupils to sketch a pentagon or hexagon.
Pupils’ Activity: Pupils identify the polygons, state properties, and attempt to sketch the requested shapes.
Learning Point: Pupils apply their understanding by identifying and sketching polygons.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

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

Define a polygon.
State three properties of a polygon.
Differentiate between regular and irregular polygons.
Mention two polygons and their corresponding number of sides.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, emphasizing the definition, properties, and types of polygons. The teacher gives pupils an assignment to draw various polygons.
Pupils’ Activity: Pupils listen to the summary, ask final questions, and note down the assignment.
Learning Point: Pupils consolidate their learning and prepare for further practice.

Lesson Keywords

Polygon – A closed plane figure bounded by three or more straight lines.
Regular Polygon – A polygon with all sides equal and all angles equal.
Irregular Polygon – A polygon with sides and/or angles that are not all equal.
Sides – The straight lines forming the boundary of a polygon.
Vertices – The points where two sides of a polygon meet.
Triangle – A polygon with three sides.
Pentagon – A polygon with five sides.
Hexagon – A polygon with six sides.
Heptagon – A polygon with seven sides.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to identify polygons with more sides (e.g., nonagon, decagon) or to find real-life examples of regular and irregular polygons. For pupils needing more support, the teacher will provide additional visual aids, one-on-one guidance, and simplified drawing exercises.

Note for teachers using this lesson plan

Ensure that all instructional materials, especially models and charts, are clearly visible to all pupils. Encourage active participation and provide constructive feedback on pupils’ sketches. Emphasize the practical application of polygons in various fields.