# Symmetry on Plane Shapes Horizontal and Vertical lines 4 Cardinal Points Primary 4 Third Term Lesson Notes Mathematics Week 9

### Subject : Mathematics

**Class** :Primary 4

**Term** :Third Term

**Week** :Week 9

**Topic** : Symmetry on Plane Shapes Horizontal and Vertical lines 4 Cardinal Points Primary 4 Third Term Lesson Notes Mathematics Week 9

**Previous Lesson** :

### Content

Good morning, class! Today, we are going to learn about symmetry in plane shapes. Symmetry is a very interesting concept that you can find in many objects around us. It’s all about balance and how things can be the same on both sides.

Now, let’s start by understanding what symmetry means. Symmetry is when an object or shape can be divided into two equal parts, and those parts are mirror images of each other. It’s like folding a shape in half, and both sides look exactly the same.

There are different types of symmetry. The most common one is called “line symmetry” or “mirror symmetry.” It means that if you draw a line down the center of the shape, both sides will be exactly the same. It’s like looking at yourself in a mirror.

Let’s take some examples to understand this better. Look at this shape here. It’s a square. If we draw a line from the top to the bottom right in the center, we can see that both sides are the same. It has four equal sides, and each angle is 90 degrees.

Now, let’s try another shape. Look at this triangle. If we draw a line from the top to the bottom, we can see that both sides are not the same. This means that the triangle does not have line symmetry. One side is longer than the other.

We can also have rotational symmetry. It means that a shape can be rotated around a central point and still look the same. Let’s take a circle, for example. If we rotate it by any angle, it will always look the same. A circle has infinite lines of symmetry.

There are also shapes that have both line symmetry and rotational symmetry. One example is the star shape. If we draw a line through the center, we can see that both sides are the same. And if we rotate it, it will still look the same at certain angles.

Now, let’s have a little activity. I will show you some shapes on the board, and I want you to tell me if they have line symmetry or rotational symmetry or both. Are you ready?

Great! Let’s start with this shape. Can you tell me if it has line symmetry or rotational symmetry or both?

[Teacher draws a shape on the board]

Student 1: It has line symmetry.

Teacher: Excellent! Now, how about this shape?

[Teacher draws another shape on the board]

Student 2: It has both line symmetry and rotational symmetry.

Teacher: Well done! You are absolutely right.

Keep practicing, and soon you’ll be able to identify symmetry in different shapes easily. Symmetry is all around us, in nature, and in many man-made objects. It helps us appreciate the beauty and balance in the world.

I hope you enjoyed learning about symmetry in plane shapes today. Don’t forget to look for symmetry in the world around you. See you next time!

- A shape that can be divided into two equal mirror images is said to have __________ symmetry. a) rotational b) line c) parallel
- The line that divides a shape into two equal mirror images is called the __________ symmetry line. a) vertical b) horizontal c) mirror
- A square has ________ lines of symmetry. a) two b) three c) four
- A triangle has ________ lines of symmetry. a) none b) one c) three
- A shape that looks the same after being rotated around a central point has ________ symmetry. a) line b) parallel c) rotational
- A circle has ________ lines of symmetry. a) infinite b) two c) zero
- An equilateral triangle has ________ lines of symmetry. a) three b) one c) two
- A shape that has both line symmetry and rotational symmetry is a ________. a) rectangle b) star c) pentagon
- A shape that has only one line of symmetry and no rotational symmetry is a ________. a) hexagon b) rhombus c) trapezoid
- A shape that has no lines of symmetry is a ________. a) square b) hexagon c) scalene triangle
- Symmetry means that one shape becomes exactly like another when you __________ it. a) rotate b) shrink c) color
- For two objects to be symmetrical, they must be the same __________ and shape. a) color b) size c) texture
- Symmetry can be achieved through various transformations such as __________, flip, or slide. a) rotate b) multiply c) divide
- A shape that remains unchanged when flipped is said to have __________ symmetry. a) rotational b) reflection c) parallel
- The line along which a shape can be folded to create symmetry is called the __________ line. a) vertical b) horizontal c) diagonal
- A face can exhibit __________ symmetry if it is the same on both sides when divided vertically. a) rotational b) line c) facial
- A square has __________ lines of symmetry. a) zero b) two c) four
- A rectangle has __________ lines of symmetry. a) one b) three c) four
- A shape that can be divided into two equal mirror images is said to have __________ symmetry. a) rotational b) line c) parallel
- A shape with both line symmetry and rotational symmetry is a __________. a) circle b) triangle c) hexagon

### Four Cardinal Points

- How many right angles are turned through by facing: North and turn clockwise to face South?
- West and turn clockwise to face North East? South and turn clockwise to face North East?
- North and turn anti clockwise to face East?
- North and turn anti clockwise to face South East?

Let’s determine the number of right angles turned for each scenario:

1. Facing North and turning clockwise to face South:

When you turn clockwise, you make a 90-degree right turn. So, you turn through 90 degrees or one right angle.

2. Facing West and turning clockwise to face North East:

Turning clockwise from West to North East involves a 135-degree turn. Since a right angle is 90 degrees, you turn through 1.5 right angles.

3. Facing South and turning clockwise to face North East:

Turning clockwise from South to North East involves a 45-degree turn. Since a right angle is 90 degrees, you turn through 0.5 right angles.

4. Facing North and turning anti-clockwise to face East:

When you turn anti-clockwise, you make a 90-degree left turn. So, you turn through 90 degrees or one right angle.

5. Facing North and turning anti-clockwise to face South East:

Turning anti-clockwise from North to South East involves a 45-degree turn. Since a right angle is 90 degrees, you turn through 0.5 right angles.

To summarize:

1. North to South (clockwise): 1 right angle

2. West to North East (clockwise): 1.5 right angles

3. South to North East (clockwise): 0.5 right angles

4. North to East (anti-clockwise): 1 right angle

5. North to South East (anti-clockwise): 0.5 right angles

Write out Name of shape and Number of lines of symmetry

a) Trapezium

b) Kite

c) Parallelogram

d) Rhombus

e) Equilateral triangle

f) Right-angled triangle

g) Isosceles triangles

h) Circle

a) Trapezium: 0 lines of symmetry

b) Kite: 1 line of symmetry

c) Parallelogram: 0 lines of symmetry

d) Rhombus: 2 lines of symmetry

e) Equilateral triangle: 3 lines of symmetry

f) Right-angled triangle: 1 line of symmetry

g) Isosceles triangles: 1 line of symmetry

h) Circle: Infinite lines of symmetry (every line passing through the center)

Remember, lines of symmetry are the lines that divide a shape into two equal halves, with both halves being mirror images of each other.

Evaluation

1. A __________ has 0 lines of symmetry.

a) Trapezium

b) Kite

c) Parallelogram

2. A __________ has 1 line of symmetry.

a) Rhombus

b) Equilateral triangle

c) Right-angled triangle

3. A __________ has 2 lines of symmetry.

a) Kite

b) Parallelogram

c) Rhombus

4. A __________ has 3 lines of symmetry.

a) Circle

b) Equilateral triangle

c) Isosceles triangle

5. A __________ has 0 lines of symmetry.

a) Right-angled triangle

b) Isosceles triangle

c) Parallelogram

6. A __________ has infinite lines of symmetry.

a) Circle

b) Rhombus

c) Trapezium

7. A __________ has 1 line of symmetry.

a) Kite

b) Circle

c) Right-angled triangle

8. A __________ has 0 lines of symmetry.

a) Equilateral triangle

b) Parallelogram

c) Isosceles triangle

9. A __________ has 2 lines of symmetry.

a) Rhombus

b) Trapezium

c) Circle

10. A __________ has 1 line of symmetry.

a) Kite

b) Right-angled triangle

c) Isosceles triangle

Remember to choose the most appropriate option (a, b, or c) for each question. Good luck!

1. Isosceles Triangle:

– An isosceles triangle has two sides of equal length and two equal angles.

– It has one line of symmetry. This line is drawn from the vertex angle (the angle opposite the base) to the midpoint of the base. The triangle can be folded along this line, and both halves will overlap perfectly.

2. Trapezium (Trapezoid in US English):

– A trapezium is a quadrilateral with only one pair of parallel sides.

– It does not have any lines of symmetry. If you try to fold it along any axis, the two halves will not match up.

3. Square:

– A square is a quadrilateral with four equal sides and four right angles.

– It has four lines of symmetry. Each line of symmetry passes through the center of the square and divides it into two equal halves horizontally, vertically, or diagonally.

4. Rhombus:

– A rhombus is a quadrilateral with four equal sides.

– It has two lines of symmetry. The lines of symmetry pass through the two pairs of opposite vertices and divide the rhombus into two equal halves.

5. Rectangle:

– A rectangle is a quadrilateral with four right angles.

– It has two lines of symmetry. The lines of symmetry pass through the midpoints of opposite sides and divide the rectangle into two equal halves.

1. Distinguishing between open and closed shapes:

– Open shapes are shapes that have one or more open sides or curves. They do not form a closed loop or boundary.

– Closed shapes are shapes that have all sides connected to form a complete loop or boundary, enclosing an area.

2. Properties of closed shapes:

– Closed shapes have a defined boundary that encloses an area.

– They have a finite number of sides or curves.

– The sum of the interior angles of a closed shape depends on the type of shape (e.g., triangles have a sum of 180 degrees, quadrilaterals have a sum of 360 degrees).

3. Appreciating the presence and use of 3-dimensional shapes in homes:

– Three-dimensional shapes, also known as solid shapes, exist all around us, including in our homes.

– Examples of 3-dimensional shapes commonly found in homes include cubes, rectangular prisms (like boxes), cylinders (like cans or bottles), and spheres (like balls or doorknobs).

– These shapes have volume and occupy space, making them useful for various purposes such as storage, furniture, appliances, and decorations.

4. Identifying right-angle, acute, and obtuse angles in a plane shape:

– A right-angle is an angle that measures exactly 90 degrees. It forms a perfect “L” shape.

– An acute angle is an angle that measures less than 90 degrees. It is smaller and more compact.

– An obtuse angle is an angle that measures greater than 90 degrees but less than 180 degrees. It is wider and more open.

5. Distinguishing between horizontal and vertical lines:

– A horizontal line is a straight line that is parallel to the horizon or the ground. It extends from left to right or right to left.

– A vertical line is a straight line that is perpendicular to the horizon or the ground. It extends from top to bottom or bottom to top.

– Horizontal lines are parallel to the x-axis on a coordinate plane, while vertical lines are parallel to the y-axis.

– In terms of orientation, horizontal lines are aligned with the horizon, while vertical lines are aligned with gravity or the direction of up and down.

### Four Cardinal Points

Good day, class! Today, we are going to learn about the four cardinal points, also known as the cardinal directions. These directions help us understand and navigate the world around us. Let’s dive in!

The four cardinal points are North, East, South, and West. Each of these directions has a specific meaning and represents a different orientation.

1. North: North is the direction towards the Earth’s North Pole. On a compass, North is represented by the letter “N” or a small arrow pointing upwards. It is the direction that points towards the top of a map.

2. East: East is the direction where the sun rises. On a compass, East is represented by the letter “E” or a small arrow pointing towards the right. If you face North, East is to your right.

3. South: South is the direction towards the Earth’s South Pole. On a compass, South is represented by the letter “S” or a small arrow pointing downwards. It is the opposite direction of North. If you face North, South is behind you.

4. West: West is the direction where the sun sets. On a compass, West is represented by the letter “W” or a small arrow pointing towards the left. If you face North, West is to your left.

Understanding the cardinal points is essential for giving and receiving directions, reading maps, and navigating our surroundings. For example, if someone tells you to go “North,” you know to move towards the top of a map or in the direction of the North Pole.

We can also use the cardinal points to describe the relative positions of objects. For instance, if we say something is to the “West” of another object, we know it is on the left side when facing the reference point.

To help remember the cardinal points, you can use the acronym “NEWS.” The first letters of North, East, South, and West spell out this word, making it easier to recall.

Now, let’s practice a little. Can you all point towards the North? Great job! How about East, South, and West? Well done!

Understanding the cardinal points will help you explore and navigate the world around you. Whether you’re reading a map, giving directions, or simply understanding your surroundings, the cardinal points will always be your guide. Keep practicing, and soon you’ll become experts!

That’s all for today’s lesson. Thank you for your attention, and I’ll see you next time!

Evaluation

1. The four cardinal points are __________, __________, __________, and __________.

a) North, East, South, West

b) Up, Down, Left, Right

c) Morning, Afternoon, Evening, Night

2. North is the direction towards the __________ Pole.

a) South

b) North

c) East

3. East is the direction where the __________ rises.

a) moon

b) sun

c) stars

4. South is the direction towards the __________ Pole.

a) North

b) South

c) East

5. West is the direction where the __________ sets.

a) moon

b) sun

c) stars

6. The letter “N” represents __________ on a compass.

a) North

b) East

c) West

7. The direction opposite to North is __________.

a) South

b) East

c) West

8. If you face North, East is to your __________.

a) right

b) left

c) front

9. If you face North, West is to your __________.

a) right

b) left

c) back

10. The acronym “NEWS” can help us remember the four cardinal points, which stands for __________.

a) North, East, South, West

b) North, East, West, South

c) North, East, Up, South

Remember to choose the most appropria te option (a, b, or c) for each question. Good luck!

Lesson Plan Presentation: Symmetry on Plane Shapes, Horizontal and Vertical Lines, 4 Cardinal Points

Primary 4, Third Term, Mathematics, Week 9

I. Learning Objectives:

By the end of this lesson, students should be able to:

1. Define symmetry and identify symmetry in plane shapes.

2. Differentiate between horizontal and vertical lines.

3. Understand and apply knowledge of the four cardinal points (North, East, South, West).

II. Embedded Core Skills:

– Critical thinking

– Visual perception

– Spatial reasoning

– Communication and language skills

III. Learning Materials:

– Whiteboard/Blackboard

– Markers/chalk

– Plane shape cut-outs (square, triangle, rectangle, etc.)

– Flashcards with horizontal and vertical lines

– Compass

– Maps or globes

– Compass rose image

IV. Presentation:

A. Introduction:

1. Greet the class and briefly review previous lessons.

2. Introduce the topics for today’s lesson: symmetry on plane shapes, horizontal and vertical lines, and the four cardinal points.

B. Symmetry on Plane Shapes:

1. Define symmetry as the property of a shape being exactly like another shape when moved through a turn, flip, or slide.

2. Show examples of symmetric plane shapes (square, rectangle, circle) and non-symmetric shapes (triangle, trapezium).

3. Discuss line symmetry and rotational symmetry.

4. Demonstrate how to identify lines of symmetry in various shapes.

5. Engage students in a hands-on activity where they fold shapes and identify lines of symmetry.

C. Horizontal and Vertical Lines:

1. Define horizontal and vertical lines as lines that are parallel to the horizon or the ground and lines that are perpendicular to the horizon or the ground, respectively.

2. Show examples of horizontal and vertical lines using flashcards or images.

3. Engage students in a sorting activity where they classify objects based on whether they have horizontal or vertical lines.

4. Provide opportunities for students to draw horizontal and vertical lines on the board or their notebooks.

D. Four Cardinal Points:

1. Introduce the concept of the four cardinal points: North, East, South, and West.

2. Show a compass rose image and explain its components.

3. Discuss the meaning and significance of each cardinal point, emphasizing their directions and relationships.

4. Use maps or globes to illustrate the cardinal points in relation to specific locations.

5. Engage students in a directional activity, where they identify and point towards the cardinal points.

V. Teacher’s Activities:

– Present and explain concepts clearly, using visual aids and real-life examples.

– Facilitate discussions and encourage student participation.

– Provide hands-on activities and opportunities for students to practice and apply their knowledge.

– Monitor and assist students during individual or group activities.

– Ask probing questions to promote critical thinking and deeper understanding.

VI. Learners’ Activities:

– Listen attentively and actively participate in class discussions.

– Engage in hands-on activities, such as folding shapes, drawing lines, and pointing towards cardinal points.

– Work individually or collaboratively on activities or assignments.

– Ask questions and seek clarification when needed.

– Share their findings or observations during class discussions.

VII. Assessment:

– Observe students’ participation and engagement during class activities.

– Review students’ completed hands-on activities or assignments for accuracy and understanding.

– Conduct individual or group discussions to assess comprehension and retention of concepts

VIII. Ten Evaluation Questions:

1. What is symmetry in plane shapes?

a) When a shape can be divided into two equal mirror images

b) When a shape has straight sides

c) When a shape has rounded corners

2. How many lines of symmetry does a square have?

a) Zero

b) Two

c) Four

3. Give an example of a shape with rotational symmetry.

a) Triangle

b) Rectangle

c) Circle

4. What is the difference between a horizontal line and a vertical line?

a) Horizontal lines are parallel to the horizon, while vertical lines are parallel to the ground.

b) Horizontal lines go from top to bottom, while vertical lines go from left to right.

c) Horizontal lines are longer than vertical lines.

5. Which cardinal point is opposite to North?

a) East

b) South

c) West

6. How many cardinal points are there?

a) Two

b) Four

c) Six

7. Give an example of a shape with both line symmetry and rotational symmetry.

a) Square

b) Trapezium

c) Kite

8. What does the letter “N” represent on a compass rose?

a) North

b) South

c) Neither

9. Which cardinal point is where the sun rises?

a) East

b) West

c) South

10. How many lines of symmetry does an equilateral triangle have?

a) Zero

b) One

c) Three

IX. Conclusion:

– Summarize the key points covered in the lesson, including symmetry on plane shapes, horizontal and vertical lines, and the four cardinal points.

– Highlight the importance of these concepts in understanding shapes, directions, and navigation.

– Encourage students to continue exploring and observing symmetry, lines, and directions in their everyday lives.

X. Homework Assignment:

– Assign students to find examples of symmetry in their environment and draw the lines of symmetry on the shapes they identify.

– Ask students to create a simple map of their classroom or home, labeling the cardinal points and indicating the directions of different objects.

Note: This lesson plan is just a guide and can be adapted or modified based on the specific needs and resources available in the classroom.