Class: Senior Secondary School 1 (SSS 1)
Term: 3rd Term
Week: 5
Age: 15 years
Duration: 45 minutes
Subject: Carpentry And Joinery
Curriculum Theme: Entrepreneurship Trade Subjects
Previous Lesson: Widening Joints in Carpentry.
Topic: IDENTIFICATION OF COMMON JOINTS – Angle Joints
Subject Matter: types of angle joints, framing joints, projects using angle joints

Specific Objectives

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

Cognitive Domain:

Define angle joints.
Identify and list different types of angle joints.
State the purpose of framing joints.

Affective Domain:

Appreciate the importance of angle joints in carpentry.
Show interest in learning various joint types.

Psychomotor Domain:

Sketch common framing joints.
Visually identify angle joints from diagrams or models.

Discuss with peers the application of angle joints in different projects.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Senior Secondary Schools.
State Unified Scheme of Work for Carpentry and Joinery SSS 1.
Carpentry and Joinery for Senior Secondary Schools by A. O. Olatunji.

Instructional Materials

The teacher will teach this lesson with the aid of:

Diagrams of various angle joints
Examples of small projects incorporating angle joints
Chalkboard/Whiteboard and markers

Rationale for the Lesson

This lesson helps pupils understand how different wood pieces are joined together, which is a basic skill in carpentry. Knowing about angle joints enables pupils to construct stable and visually appealing wooden structures in their daily lives and future careers.

Prerequisite/Previous Knowledge

Pupils should have basic knowledge of carpentry hand tools and common types of wood used in construction.

Lesson Content/Board Summary

IDENTIFICATION OF COMMON JOINTS – ANGLE JOINTS

Definition of Angle Joints

Angle joints are woodworking joints used to connect two pieces of wood at an angle, most commonly 90 degrees, to form corners or frames. They provide strength and aesthetic appeal to wooden structures.

Types of Angle Joints

The following are common types of angle joints:

Butt Joint: Two pieces of wood are simply butted together at an angle and fastened. It is one of the simplest but weakest joints.
Mitre Joint: Two pieces of wood are cut at matching angles (e.g., 45 degrees for a 90-degree corner) and joined together. It creates a clean, seamless appearance.
Halving Joint (Corner Halving Joint): Half the thickness of each piece of wood is removed, allowing them to overlap and fit flush, forming a strong corner.
Dovetail Joint: Characterised by interlocking ‘pins’ and ‘tails’, this joint offers excellent mechanical strength and resistance to being pulled apart, often used in drawers and boxes.
Bridle Joint: Similar to a mortise and tenon joint but typically used at corners or ‘T’ intersections, where one piece has a tenon cut on its end, fitting into a mortise in the other piece.

Framing Joints

Framing joints are specific types of angle joints used in constructing frames for windows, doors, cabinets, and other structures. They are designed to provide rigidity and strength to the frame while maintaining the desired angles.

Examples of angle joints commonly used as framing joints include:

Mitre joints (for aesthetic corners)
Halving joints (for strong, flush corners)
Mortise and tenon joints (for heavy-duty framing)

Projects Using Angle Joints

The following are examples of projects where angle joints are commonly used:

Picture frames and mirror frames
Small boxes and chests
Cabinet doors and carcases
Window frames and door frames
Furniture such as tables and chairs (for leg and rail connections)

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, reviews the previous lesson on basic carpentry tools, and then introduces the new topic by asking pupils how two pieces of wood can be joined together to form a corner.
Pupils’ Activity: Pupils respond to the teacher’s questions and listen attentively.
Learning Point: Pupils are prepared for the new lesson on angle joints.

Step 2: Explanation of Angle Joints

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines angle joints and explains their general purpose in carpentry, using simple language. The teacher may show a simple diagram of an angle joint.
Pupils’ Activity: Pupils listen, take notes, and ask questions for clarification.
Learning Point: Pupils understand what angle joints are and why they are used.

Step 3: Identification of Types of Angle Joints

Time: 10 minutes
Teaching Skill: Demonstration/Visual Aids
Teacher’s Activity: The teacher presents various diagrams or models of angle joints (e.g., butt, mitre, halving, dovetail, bridle joints). The teacher explains the characteristics of each type and how they are made.
Pupils’ Activity: Pupils observe the diagrams/models, identify the different types, and note their features.
Learning Point: Pupils can identify and differentiate between common types of angle joints.

Step 4: Focusing on Framing Joints

Time: 8 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains what framing joints are and how angle joints are specifically applied in constructing frames. The teacher uses diagrams to show how mitre or halving joints are used in a window frame. The teacher then guides pupils to sketch one or two simple framing joints.
Pupils’ Activity: Pupils listen, observe the diagrams, and sketch the framing joints as instructed.
Learning Point: Pupils understand the application of angle joints in framing and can sketch them.

Step 5: Discussing Projects Using Angle Joints

Time: 5 minutes
Teaching Skill: Discussion/Brainstorming
Teacher’s Activity: The teacher leads a discussion on various carpentry projects that require the use of angle joints. The teacher prompts pupils to suggest examples from their environment.
Pupils’ Activity: Pupils contribute ideas and list projects such as picture frames, small boxes, and cabinet doors.
Learning Point: Pupils can identify practical applications of angle joints in real-world projects.

Step 6: Class Activity/Practical Application

Time: 5 minutes
Teaching Skill: Practical Application
Teacher’s Activity: The teacher distributes simple diagrams of unfinished projects and asks pupils to identify which angle joint would be most suitable for specific corners or connections.
Pupils’ Activity: Pupils analyze the diagrams and orally suggest appropriate angle joints.
Learning Point: Pupils apply their knowledge to suggest suitable joints for different scenarios.

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 an angle joint.
Mention three types of angle joints.
What is the primary purpose of a framing joint?
List two common carpentry projects where angle joints are used.

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 importance of correctly identifying and using different angle joints. The teacher assigns homework for pupils to draw and label three different angle joints.
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils consolidate their learning and are given tasks for reinforcement.

Lesson Keywords

Angle Joint – A joint connecting two pieces of wood at an angle, usually 90 degrees.
Butt Joint – A simple joint where two pieces of wood are joined end to end or edge to edge.
Mitre Joint – An angle joint where two pieces are cut at an angle to form a corner.
Halving Joint – A joint where half the thickness of each piece of wood is removed to create an overlap.
Dovetail Joint – A strong interlocking joint with ‘pins’ and ‘tails’.
Framing Joint – Any joint used specifically for constructing frames.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to identify more complex variations of angle joints or design a simple project incorporating multiple joint types. For pupils needing more support, the teacher will provide simplified diagrams and offer one-on-one guidance during sketching activities.

Note for teachers using this lesson plan

Ensure to have clear, large diagrams or actual models of the joints for effective demonstration. Encourage pupils to ask questions and share their observations. Safety precautions related to woodworking tools should always be discussed before any practical activity.