Lesson Notes By Weeks and Term - Junior Secondary 2

TERM – 1^ST TERM

WEEK FIVE

Class: Junior Secondary School 2

Age: 13 years

Duration: 40 minutes of 5 periods each

Date:

Subject: BASIC TECHNOLOGY

Topic: GEOMETRIC CONSTRUCTION

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Define lines
2. Identify and Draw Lines of Various Types
3. Identify the Use of each lines.
4. Bisect a line.

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers,

demonstration, videos from source

INSTRUCTIONAL MATERIALS:   Videos, loud speaker, textbook, pictures, mathematical sets. Drawing materials.

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

GEOMETRIC CONSTRUCTION

Lines

A line is a one-dimensional figure, which has length but no width. A line is made of a set of points which is extended in opposite directions infinitely. It is determined by two points in a two-dimensional plane. The two points which lie on the same line are said to be collinear points.

Types of Lines

The following are types of lines

1. Thin Continuous Line: A line that is consistently drawn without interruptions, and it has a small or minimal thickness. It is used for construction lines, dimension lines, projection lines, extension lines, and for hatching.
2. Thick Continuous Line: A line with a consistent and unbroken appearance, but with a greater thickness compared to a thin line. The continuous thick line is used to show visible outlines or edges of a component or assembly
3. Dashed Thin Line: A line composed of short dashes with spaces in between, giving the appearance of a broken or interrupted line. It maintains a thin thickness. The dashed narrow lines are used to represent the edges that are not directly visible.
4. Arrow Head Line: A line that includes arrowheads at one or both ends, indicating the direction of movement or flow. Arrowheads are used at the end of dimension lines and leaders. They are also used to indicate the direction of a cutting or viewing plane line.
5. Continuous Thin Zigzag Line: A line characterized by a pattern of connected short, angled segments resembling a series of "Z" shapes. It maintains a thin and continuous appearance but has a zigzag pattern.
6. A thin continuous wavy line is a line that is consistently drawn with a wave-like pattern and maintains a relatively small thickness. Unlike a straight continuous line, the thin continuous wavy line features a series of curves, creating a flowing and undulating appearance.
7. Dotted Lines: Lines made up of dots, dotted lines are used to represent hidden or phantom lines. They indicate parts of an object that are not visible in the view being represented

 Bisection and Division of Lines

Procedure

1. Draw a given line of any desirable length and label AB
2. Using a compass with a radius half of the line in (I) above. Place the point of the compasson a and draw an arc above and below line AB.
3. With a centre B, using the same radius draw and arc above and below line AB to cut the first arc at Can D.
4. Using a ruler, draw a line to join CD. The point where the two lines meet should be labeled point P.

Now CD is a perpendicular bisector because line CD bisect AB at a right angle.

EVALUATION: 1. What is a line?

2. Mention 5 types of lines and state their uses
3. Bisect a horizontal line.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively