# Meaning and Types of Angles | The Use of Parallel and Transversal Lines to Determine Corresponding Angles, Alternate Angles and Vertical Opposite Angles Term 3 Week 4 Mathematics

### MATHEMATICS

THIRD TERM

WEEK 4

PRIMARY 5

THEME – MENSURATION AND GEOMETRY

PREVIOUS LESSON – Plane Shapes and Their Properties – Triangles, Quadrilaterals and Circles Primary 5 (Basic 5) Term 3 Week 3 Mathematics

#### LEARNING AREA

1. Introduction

2. Meaning and Types of Angles

3. Corresponding Angles

4. Alternate Angles

5. Vertical Opposite Angles

6. Lesson Evaluation and Weekly Assessment (Test)

#### LEARNING OBJECTIVES

By the end of the lesson, most pupils should have attained the following objectives –

1. explain the meaning of angle with appropriate illustrations.

3. state and draw different types of angles.

4. use the parallel and transversal limes to determine the corresponding angles, alternate angles and opposite angles.

#### ENTRY BEHAVIOUR

The pupils can identify the space between two or more lines as an angle.

#### INSTRUCTIONAL MATERIALS

The teacher will teach the lesson with the aid of chart showing different types of angles.

#### 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 1 – INTRODUCTION

ACTIVITY 1 – CONCEPT OF ANGLE

Materials Needed – Plain sheet of papers, rulers and pencil.

Teacher organizes pupils in groups or pairs depending on the size of the class to carry out the following instructions,

• Draw a straight line.
• Draw another straight line from the starting or end point of the first line.

Teacher’s remark – A line is a straight or curved mark made by marking materials like pen, pencil, etc.

MEANING OF ANGLE

An angle is the space between two intersecting lines.

ACTIVITY 2 – GROUP WORK

Materials Needed – Plain sheet of papers, protractors, rulers, pencil chart showing different types of angles such as

Teacher uses the existing groups or pairs and guides them to measure and record correctly each of the above angle.

Record,

1.

2.

3.

4.

5.

ACTIVITY 3 – TYPES OF ANGLES

An angle is the space between two intersecting lines.

There are different types of angles,

1. Right angle

2. Acute angle

3. Obtuse angle

4. Straight angle or angle on a straight line

5. Reflex angle

6. Angle on a point

7. Complimentary angle

8. Supplementary angle

1. RIGHT ANGLE

Right angle is the angle that forms a square corner.

It is an angle that is always equal 90°.

2. ACUTE ANGLE

Acute angle is any angle that less than 90°.

It is an angle between 1° – 90°.

Acute angle is greater 0° and less than 90°.

3. OBTUSE ANGLE

Obtuse angle is any angle that is larger (bigger) than right angle.

It is an angle between 91° – 179°.

Obtuse is greater than greater 90° and less than 180°.

4. STRAIGHT ANGLE

Straight angle is any angle that is equal to 180°.

It is twice of right angles.

Straight angle is equal to 180°.

5. REFLEX ANGLE

Reflex angle is any angle that is greater than 180° and less than 360°.

6. ANGLE AT A POINT

Angel at a point is any angle that is equal to 360°.

7. COMPLIMENTARY ANGLES

Complimentary angles are two angles that are sum up to 90º.

Two angles are said be complimentary angles, when they add up to 90°.

8. SUPPLEMENTARY ANGLE

Supplementary angles are two angles that are sum up to 180º.

Two angles are said be supplementary angles, when they add up to 180°.

#### LESSON 2 – PARALLEL AND TRANSVERSAL LINES

ACTIVITY 1 – INTRODUCTION

A line is a straight or curved mark made by marking materials like pen, pencil, etc.

An angle is the space between two intersecting lines.

DRAWING PARALLEL AND TRANSVERSAL LINES

Based on the existing groups or pairs, teacher guides pupils to,

1. draw two straight lines

2. draw a line that cross the two straight lines.

3. mark the angles formed.

4. count the number of angles on the transversal lines.

PARALLEL LINES

Parallel lines are lines in a plane that are always the same distance apart like equal sign.

### ______________________

TRANSVERSAL LINES

Transversal line are lines that intersect two straight lines or parallel lines at distinct points.

ACTIVITY 2 – TRANSVERSAL LINES AND ANGLES

Transversal angles are angles formed when a straight line cuts the two parallel lines.

#### LESSON 3 – TRANSVERSAL ANGLES

ACTIVITY 1 – TRANSVERSAL ANGLES

The following are transversal angles,

1. Corresponding angles

2. Alternate Interior Angles

3. Alternate Exterior Angles

4. Opposite Angles

ACTIVITY 2 – CORRESPONDING ANGLES

Corresponding angles are angles formed in the same position when a line cross the parallel lines.

In the above, all the following are corresponding angles –

• A and E
• C and G
• B and F
• D and H

ACTIVITY 3 – ALTERNATE ANGLES

Alternate angles are angles that are on the opposite sides of the transversal line.

All alternate angles are equal angles.

There are two (2) types of alternate angles, interior and exterior angles.

The angles formed inside the opposite sides are known are as interior angles. While angles formed outside opposite sides are known as exterior angles.

In the above, the following are alternate interior angles –

• C and F
• D and E

While, the following are alternate exterior angles –

• A and H
• B and G

ACTIVITY 4 – OPPOSITE ANGLES

Opposite angles are angles that are directly opposite to each on the transversal line.

These angles are equal angles and also known as vertical angles.

The following are vertical or opposite angles,

• A and D
• B and C
• E and H
• F and G

ACTIVITY 5 – CO – INTERIOR ANGLES

Co – interior angles are angles between two parallel angles.

These are on the same sides of the transversal line.

The sum of the co – interior angles is equal to 180°.

In the above diagram, the following are co – interior angles –

• D and F, D + F = 180°
• C and E, C + E = 180°

5. SUPPLEMENTARY ANGLES

Supplementary angles are two angles that are sum up to 180º on the transversal line.

Supplementary angles are as follows:

• A and B, A + B = 180º
• A and C
• C and D
• B and D, etc.

#### LESSON 4 – WORKING EXAMPLE AND EXERCISE

WORKING EXAMPLE

If A =46°, find the B, C, D, E, F, G and H.

SOLUTIONS

If A = 46°, A + B = 180 (supplementary angles).

B = 180° – 46° = 134°

• B = C = 134°(opposite angles)
• A = D = 46° (opposite angles)
• A = E = 46° (corresponding angles)
• E = H = 46° (opposite angles)
• B = F = 134° (corresponding angles)
• F = G = 134° (corresponding angles)

Therefore, A = 46°, B = 134°, C = 134°, D =46°, E = 46°, F = 134°, G = 134° and H = 46°.

WORKING EXERCISE

Find the letter a – g,

LESSON 5 – REVISION AND WEEKLY ASSESSMENT (TEST)

### 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. Teacher organizes the pupils in groups or pair depending on the size of the class.

3. Teacher guides pupils draw lines to form angels.

Pupil’s Activities – Use lines for form angles.

4. Teacher uses the pupil’s activities in step 3 introduce the lesson.

Pupil’s Activities – Pay attention to the lesson introduction to understand the concept of the lesson.

5. Teacher uses the pupils drawings to discuss the meaning and types of angles with appropriate examples from pupil’s drawings.

6. Teacher guides pupils to differentiate between the types of angles using appropriate examples.

Pupil’s Activities – Identify and describe each type of angle.

7. Teacher guides pupils as groups or pairs to drawn transversal line on parallel lines.

Pupil’s Activities – Draw a transversal line.

8. Teacher guides pupils to identify and count number of angles formed.

Pupil’s Activities – State the number of angles formed by transversal line.

9. Teacher tells the groups or pairs that the angles formed by transversal line are known as transversal angles.

Pupil’s Activities – Different between transversal line and angles.

10. Teacher uses the angles formed by transversal line to discuss and guides pupils to determine the transversal angles such as corresponding angles, alternate angles, etc.

Pupil’s Activities – Identity and different between different transversal angles.

11. Teacher summarizes each of the lesson on the board with appropriate evaluation.

Pupil’s Activities – Participate actively in the summary of the lesson by responding correctly in the questions and write as instructed.

#### CONCLUSION

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

#### NEXT LESSON

The Nets of Three Dimensional Shapes (Prisms and Pyramids) | Making Three Dimensional Shapes Using their Nets Primary 5 (Basic 5) Term 3 Week 5 Mathematics

#### LESSON EVALUATION

1. explain the meaning of angle.

2. list and explain types of angles.

3. different between transversal line and transversal angles.

4. draw a transversal line on parallel lines.

5. differentiate between transversal line and parallel lines.

6. Find the following letters,