Geometrical Construction Angles Exploring Angles: Definition, Types, and Practical Uses Basic Technology JSS 2 First Term Lesson Notes Week 6
Basic Technology JSS 2 First Term Lesson Notes Week 6
Subject: Basic Technology
Class: JSS 2
Term: First Term
Week: 6
Age: 12 years
Topic: Angles
Sub-topic: Definition, Types, and Uses
Duration: 40 minutes
Behavioural Objectives:
By the end of the lesson, students should be able to:
- Define what an angle is.
- Identify and describe different types of angles.
- Explain the practical uses of angles in daily life.
Keywords:
- Angle: The figure formed by two rays or lines meeting at a point.
- Acute Angle: An angle less than 90 degrees.
- Obtuse Angle: An angle greater than 90 degrees but less than 180 degrees.
- Right Angle: An angle equal to 90 degrees.
- Straight Angle: An angle equal to 180 degrees.
Set Induction:
The teacher asks students to look around the classroom and identify objects that form angles (e.g., corners of books, tables).
Entry Behaviour:
Students should have a basic understanding of shapes and lines from previous lessons.
Learning Resources and Materials:
- Protractors
- Rulers
- Whiteboard and markers
- Visual aids showing different angles
- Real-life examples of angles (e.g., doors, windows)
Building Background/Connection to Prior Knowledge:
Students have encountered angles in geometry and everyday objects.
Embedded Core Skills:
- Critical thinking
- Observation
- Measurement
Learning Materials:
- Angle identification charts
- Reference books on angles and their properties
Reference Books:
- Lagos State Scheme of Work
- Basic Technology for Junior Secondary Schools by NERDC
Instructional Materials:
- Protractors
- Rulers
- Graph paper
Content:
I. Definition and Explanation of Angles
- Definition: An angle is formed when two lines or rays meet at a common point called the vertex.
- Components of an Angle:
- Vertex: The point where two lines meet.
- Arms: The two rays that form the angle.
II. Types of Angles
- Acute Angle:
- Definition: An angle less than 90 degrees.
- Example: The angle between the hands of a clock at 10:10.
- Right Angle:
- Definition: An angle exactly equal to 90 degrees.
- Example: The corner of a square or rectangle.
- Obtuse Angle:
- Definition: An angle greater than 90 degrees but less than 180 degrees.
- Example: The angle between the hands of a clock at 10:15.
- Straight Angle:
- Definition: An angle equal to 180 degrees.
- Example: A straight line.
- Reflex Angle:
- Definition: An angle greater than 180 degrees but less than 360 degrees.
- Example: The angle between the hands of a clock at 2:30.
III. Uses of Angles
- Angles are used in construction to ensure structures are built accurately.
- Angles help in navigation and surveying.
- They are crucial in art and design for creating perspectives.
- Angles are used in sports for trajectory calculations (e.g., basketball).
- They play a role in technology, such as in camera lenses and robotics.
15 Fill-in-the-Blank Questions:
- An angle is formed by two ______ meeting at a point.
a) Lines
b) Circles
c) Squares
d) Triangles - An angle less than 90 degrees is called an ______ angle.
a) Obtuse
b) Acute
c) Right
d) Straight - A right angle is equal to ______ degrees.
a) 45
b) 90
c) 180
d) 360 - An angle greater than 90 degrees is called an ______ angle.
a) Acute
b) Right
c) Obtuse
d) Reflex - A straight angle measures ______ degrees.
a) 90
b) 180
c) 270
d) 360 - The point where two rays meet is called the ______.
a) Line
b) Vertex
c) Arm
d) Angle - A reflex angle is an angle that measures ______ degrees.
a) Less than 90
b) Between 90 and 180
c) Greater than 180
d) Exactly 360 - Angles are important in ______ for ensuring accuracy.
a) Cooking
b) Gardening
c) Construction
d) Cleaning - The angle formed by the hands of a clock at 3:00 is a ______ angle.
a) Acute
b) Right
c) Obtuse
d) Reflex - Angles help in ______ and surveying.
a) Painting
b) Navigation
c) Shopping
d) Writing - An angle of 270 degrees is called a ______ angle.
a) Acute
b) Obtuse
c) Reflex
d) Right - The arms of an angle are the ______ that form it.
a) Lines
b) Angles
c) Points
d) Rays - Angles are crucial in ______ for creating perspectives.
a) Music
b) Art
c) Cooking
d) Writing - The symbol for an angle is often represented by the ______ sign.
a) +
b) =
c) ∠
d) % - An example of an obtuse angle is the angle formed at ______.
a) 2:00
b) 3:00
c) 5:00
d) 7:00
15 FAQs with Answers:
- What is an angle?
An angle is formed when two rays meet at a point. - What are the types of angles?
Types include acute, right, obtuse, straight, and reflex angles. - What is a right angle?
A right angle measures exactly 90 degrees. - How do you measure an angle?
You can use a protractor to measure angles. - What is an acute angle?
An acute angle is less than 90 degrees. - Why are angles important in construction?
Angles ensure that structures are built correctly and safely. - What does it mean to bisect an angle?
To bisect an angle means to divide it into two equal parts. - What is a straight angle?
A straight angle measures exactly 180 degrees. - How are angles used in navigation?
Angles help determine direction and location. - What is a reflex angle?
A reflex angle is greater than 180 degrees but less than 360 degrees. - Can angles be negative?
Angles are typically measured as positive values. - How are angles used in sports?
Angles are used to calculate trajectories and optimize performance. - What tools do I need to draw angles?
You need a protractor and a ruler. - Can an angle be formed by lines that do not meet?
No, an angle requires two rays or lines to meet at a point. - How do angles help in art?
Angles create perspectives and dimensions in artistic designs.
Presentation Steps:
Step 1:
The teacher revises the previous topic about geometric lines and their properties.
Step 2:
The teacher introduces the new topic by explaining what angles are and their types.
Step 3:
The teacher allows pupils to contribute, asking them to identify angles in the classroom and in real life.
Teacher’s Activities:
- Define angles and their types.
- Demonstrate measuring angles using a protractor.
- Facilitate discussions on the importance of angles.
Learners’ Activities:
- Identify angles around them.
- Practice measuring and drawing different types of angles.
- Work in pairs to create examples of angles using protractors.
Assessment:
- Define an angle and give an example.
- What is an acute angle?
- Describe a right angle.
- How do you measure an obtuse angle?
- Provide two real-life examples of angles.
- Explain what a reflex angle is.
- Why are angles important in navigation?
- How do you bisect an angle?
- What tool is used to measure angles?
- Describe a situation where angles are important in sports.
Conclusion:
The teacher goes around to mark the students’ work and provides feedback on their understanding of the topic.