# Area of Trapezium (Primary 6)

MATHEMATICS

SECOND TERM

WEEK 5

PRIMARY 6

THEME – MEASUREMENT

PREVIOUS LESSON – Second Term Scheme of Work and Plan Lesson Notes for MATHEMATICS Week 1 to Week 12 Primary Schools

TOPIC – AREA OF TRAPEZIUM

PERFORMANCE OBJECTIVES

By the end of the lesson, the pupils should have attained the following objectives (cognitive, affective and psychomotor) and should be able to –

1. calculate the areas of figures which can be divided into rectangles and or triangles;

2. calculate land areas in hectares.

ENTRY BEHAVIOUR

INSTRUCTIONAL MATERIALS

The teacher will teach the lesson with the aid of:

1. Nail board

2. Rubber bands

3. Cut out shape forms cardboards

4. Land plan

METHOD OF TEACHING – Choose a suitable and appropriate methods for the lessons.

Note – Irrespective of choosing methods of teaching, always introduce an activities that will arouse pupil’s interest or lead them to the lessons.

REFERENCE MATERIALS

1. Scheme of Work

2. 9 – Years Basic Education Curriculum

3. Course Book

4. All Relevant Material

5. Online Information

CONTENT OF THE LESSON

LESSON LESSON ONE – INTRODUCTION TO TRAPEZIUM

Teacher’s/Pupil’s Activities 1 – Making Trapezium with Two Faces of Cuboid

Teacher’s Activities

As in the previous lesson – Perimeter of Regular and Irregular Shapes (Primary 6), guides the pupils to recall the characteristics of cuboid.

Pupil’s Response

Cuboid has 6 faces, 8 vertices (corners) and 12 edges.

Teacher’s/Pupil’s Activities 2 – Cutting Out Two Faces/Rectangles of Cuboid

Face 1

Face 2

Teacher’s Activities – Let pupils identify each face as rectangle and recall the characteristics of rectangle.

Pupil’s Activities 3 – Identifying The Characteristics of Rectangle

Rectangle is a four (4) sides shape with two (2) of length and four (4) vertices (corners).

Teacher’s/Pupil’s Activities 4 – Cutting Out Triangle from One of the Rectangle

That’s,

Pupil’s Activities – Making Trapezium

Rectangle + Triangle

Triangle + Rectangle + Triangle

Teacher’s remark – The above shape is called trapezium. There are two (2) kinds of trapezium.  Rectangle + Triangle and Triangle + Rectangle + Triangle

Pupil’s Activities 5 – Exercises/Take Home/Project

Display the the two trapezium on the board and ask pupils to draw Triangle with Rectangle + Triangle and Triangle + Rectangle + Triangle

LESSON TWO – AREA OF TRAPEZIUM

Teacher’s/Pupil’s Activities 1 – Area of Trapezium

Teacher’s Activities – Let pupils to find the area of the two rectangles.

First rectangle,

Second rectangle,

Area of the first rectangle,

= 6 cm x 4 cm

= 24 cm²

Teacher’s activities – Each of the rectangle has the same area. Divide the second rectangle through the diagonal to form triangle and ask the pupils, if the areas of this rectangle is 24 cm² , what is the area of this triangle?

Expected Response,

The area of the rectangle is 24 cm². Therefore, the area of triangle is 12 cm² because it is the triangle is half (½) of the rectangle.

Expected Response, 24 cm² + 12  cm² = 36 cm².

Teacher’s remark – The area of rectangle is Length x Breath. Since the triangle is half (½) of rectangle. The area of rectangle is written as

½(a+b)h. That’,  half of the sum of parallel lines of trapezium multiple by its height.

LESSON THREE – APPLICATION OF ½(a + b)h

Teacher’s/Pupil’s Activities 1 – Identify each part of trapezium

Area of Trapezium = ½(a + b)h

Teacher’s/Pupil’s Activities 2 – Area of Trapezium

Find the area of trapezium,

Area of Trapezium = ½(a + b)

Where a = 4 cm, 12 cm and h = 12 cm

= ½(4 cm + 12 cm) x 4 cm

= 1/2 x 16 cm x 4 cm

= 1 x 16 cm x 2 cm

= 32 cm²

Pupil’s Activities 3 – Exercises/Take Home

Find the area of trapezium,

LESSON FOUR – CONTINUATION OF LESSON 3

PRESENTATION

To deliver the lesson, the teacher adopts the following steps:

1. To introduce the lesson, the teacher revises the previous lesson. Based on this, he/she asks the pupils some questions;

2. Guides pupils to draw and break the trapezium into two parts (rectangle and triangle) – The area of the trapezium is (Area of Rectangle) + (Area o Triangle) i.e. (L × H) + (h × b / 2).

Pupil’s Activities – Calculate the area of the given trapezium.

3. Guides pupils to calculate land areas expressing the units in hectares.

Pupil’s Activities – Find areas in m² and convert to hectares.

CONCLUSION

To conclude the lesson for the week, the teacher revises the entire lesson and links it to the following week’s lesson.

LESSON EVALUATION

Pupils to:

1. find the areas of figures which can be divided into rectangles and triangles;

2. calculate the areas of the given shapes or figures.

3. calculate given areas in square metres and convert to hectares.