Lesson guide gr. 3 chapter iii -geometry v1.0

Lesson Guide

In

Elementary Mathematics

Grade 3

Reformatted for distribution via DepEd LEARNING RESOURCE MANAGEMENT and DEVELOPMENT SYSTEM PORTAL

DEPARTMENT OF EDUCATION BUREAU OF ELEMENTARY EDUCATION

in coordination with ATENEO DE MANILA UNIVERSITY

2010

Chapter III

Geometry

INSTRUCTIONAL MATERIALS COUNCIL SECRETARIAT, 2011

Lesson Guides in Elementary Mathematics Grade III Copyright © 2003 All rights reserved. No part of these lesson guides shall be reproduced in any form without a written permission from the Bureau of Elementary Education, Department of Education.

The Mathematics Writing Committee

GRADE 3

Region 3

Agnes V. Canilao – Pampanga Josefina S. Abo – Tarlac City Alma Flores – Bataan

Region 4 - A

Cesar Mojica – Regional Office Marissa J. de Alday – Quezon Henry P. Contemplacion – San Pablo City

Region 4 – B

Felicima Murcia – Palawan National Capital Region (NCR)

Laura N. Gonzaga – Quezon City Dionicia Paguirigan – Pasig/San Juan Yolita Sangalang – Pasig/San Juan

Bureau of Elementary Education (BEE) Elizabeth J. Escaño Galileo L. Go Nerisa M. Beltran

Ateneo de Manila University

Pacita E. Hosaka

Support Staff

Ferdinand S. Bergado Ma. Cristina C. Capellan Emilene Judith S. Sison Julius Peter M. Samulde Roy L. Concepcion Marcelino C. Bataller Myrna D. Latoza Eric S. de Guia - Illustrator

Consultants

Fr. Bienvenido F. Nebres, SJ – President, Ateneo de Manila University Ms. Carmela C. Oracion – Principal,

Ateneo de Manila University High School Ms. Pacita E. Hosaka – Ateneo de Manila University

Project Management

Yolanda S. Quijano – Director IV Angelita M. Esdicul – Director III

Simeona T. Ebol – Chief, Curriculum Development Division Irene C. Robles – OIC - Asst. Chief, Curriculum Development Division

Virginia T. Fernandez – Project Coordinator

EXECUTIVE COMMITTEE

Jesli A. Lapus – Secretary, Department of Education Teodosio C. Sangil, Jr. – Undersecretary for Finance and Administration

Jesus G. Galvan – OIC - Undersecretary for Programs and Projects Teresita G. Inciong – Assistant Secretary for Programs and Projects

Printed By: ISBN – 971-92775-2-1

iii

TABLE OF CONTENTS

Introduction .................................................................................................................................. iv Matrix ........................................................................................................................................ v

III. GEOMETRY

Visualizing Perpendicular, Parallel and Intersecting Lines ............................................. 1 Identifying Perpendicular, Parallel and Intersecting Lines .............................................. 4 Visualizing Congruent Line Segments ............................................................................ 9 Identifying Congruent Line Segments. ............................................................................ 12 Turns ............................................................................................................................... 15 Flips ............................................................................................................................... 19 Slides............................................................................................................................... 23 Forming Simple Symmetrical Designs ............................................................................ 27

iv

I N T R O D U C T I O N

The Lesson Guides in Elementary Mathematics were developed by the

Department of Education through the Bureau of Elementary Education in

coordination with the Ateneo de Manila University. These resource materials

have been purposely prepared to help improve the mathematics instruction in

the elementary grades. These provide integration of values and life skills using

different teaching strategies for an interactive teaching/learning process.

Multiple intelligences techniques like games, puzzles, songs, etc. are also

integrated in each lesson; hence, learning Mathematics becomes fun and

enjoyable. Furthermore, Higher Order Thinking Skills (HOTS) activities are

incorporated in the lessons.

The skills are consistent with the Basic Education Curriculum

(BEC)/Philippine Elementary Learning Competencies (PELC). These should be

used by the teachers as a guide in their day-to-day teaching plans.

v

MATRIX IN ELEMENTARY MATHEMATICS Grade III

COMPETENCIES VALUES INTEGRATED STRATEGIES USED MULTIPLE INTELLIGENCES

TECHNIQUES With HOTS

III. Geometry

A. Comprehension of Line and Line

Segment

1. Draw perpendicular, parallel, intersecting lines

1.1 Visualize perpendicular, parallel and intersecting lines

Cooperation Concept development Acting out the problem

Outdoor activities (Naturalist)

1.2 Identify perpendicular, parallel and intersecting lines

Sportsmanship Drawing pictures Imagery (Musical) Games (Bodily kinesthetic)

2. Draw congruent line segments

2.1 Visualize congruent line segments Appreciation of the uniqueness of an object or person

Concept/Concept development Listing Drawing pictures

Graphs (Spatial) Games (Bodily kinesthetic)

2.2 Identify congruent line segments Neatness Constructing figures Movements (Bodily Kinesthetic)

B. Comprehension of Slides, Flips, Turns

1. Determine which motion, turn, flip or slide creates a given tessellation

1.1 Visualize the turn of figures Working harmoniously with others

Concept development Drawing (Spatial)

1.2 Identify flip Orderliness Concept development Drawing (Spatial)

1.3 Visualize slide Following standard set Concept development Drawing (Spatial)

C. Comprehension of Symmetry

1. Form simple symmetrical designs out of given shapes(triangles and squares)

Creativity Modeling Demonstrating Tracing (Spatial) Cooperative groups(Interpersonal)

1

Visualizing Perpendicular, Parallel and Intersecting Lines

I. Learning Objectives

Cognitive: Visualize perpendicular, parallel and intersecting lines Psychomotor: Show perpendicular, parallel and intersecting lines through models Affective: Show cooperation in small group activities

II. Learning Content Skill: Comprehension of line and line segments Reference: BEC PELC III A 2.1 Materials: pictures, pieces of string, sticks Value: Cooperation

III. Learning Activities

A. Preparatory Activities

1. Drill

Match column A with column B. The teacher may print these in cartolina strips and give them to his/her pupils. Use color-coding to facilitate the drill.

a. dotted lines

b. broken lines

c. curve lines

d. clockwise

e. counter clockwise

2. Motivation

Ask the pupils to go outside. Have them form the following lines.

Group 1 Group 2 Group 3

B. Developmental Activities

1. Presentation Grace likes to play pick-up sticks, a Chinese game. When she threw the sticks on the floor she found them in these positions.

What letter is similar to the lines that Group I formed? Group 2? What object is similar to the lines of Group 3?

2

(Figure A) (Figure B) (Figure C)

a. Ask the pupils what are the lines can be found in each figure: Figure A ________________ __________________ Figure B ________________ __________________ Figure C ________________ __________________

b. Ask the following questions: Does line AB meet line CD? If we extend the lines at both ends, will they meet?

c. Look at the corners of figure B. What do they form? What letter is similar to figure B? How many lines are shown in figure C? Name the lines. Is point O on line BW? Is point O on line YT? What is the point where the two lines meet? What letter in the alphabet is similar to this figure?

Introduce the terms parallel lines, intersecting lines and perpendicular lines.

d. Can you recall the figures that you form outside the classrooms? What do we call the line formed by group 1? Group 2? Group 3?

e. Present another example. Use cartolina strips. Discuss again.

2. Guided Practice

a. Dyads:

1. Group students in pairs and give each pupil a string. 2. Let them show in front of the class perpendicular, parallel and

intersecting lines. (Let the pupils hold the string at both ends during the presentation)

b. Divide the class into three or four groups. Provide each group pictures and a cartolina or manila paper. Ask the pupils to encircle the perpendicular, parallel and intersecting lines in the pictures. Let them paste their work on the cartolina. They may use this format:

Intersecting lines Parallel lines Perpendicular lines

c. Form two groups. Ask them to make a big model of perpendicular, parallel and intersecting lines. Caution: Splitting is not allowed. They may do this by lying on the floor of the room

C A

D B H F

E

G

B

T

W Y

O

3

Ask: What should you do as a member of your group? Why is it good to cooperate with your group?

3. Generalization

How do you differentiate parallel lines from intersecting lines? Parallel lines to perpendicular lines?

What can you say about parallel lines, intersecting lines, and perpendicular lines?

Lines that will never meet are called parallel lines. Lines that meet are intersecting lines. Lines that form a right angle are called perpendicular lines

C. Application

1. Ask the pupils to draw perpendicular lines, parallel lines, and intersecting lines on the air. 2. Ask the pupils to give examples each of intersecting, parallel, and perpendicular lines found

in the room. IV. Evaluation

A. Identify the kinds of lines referred to in the following. Write P for perpendicular, PL for parallel, IL for intersecting lines.

1. hands of the clock at 3 o’ clock 2. capital letter L 3. letter x 4. capital letter T 5. striped T-shirt

B. Study the map, then fill in the blanks with parallel, intersecting, and perpendicular lines.

MAP

1. Lopez Street is _____________ to Ruiz Street. 2. Rizal Street is ______________ to Lopez Street. 3. Malvar Street is _____________ to Luna Street. 4. Luis Street and Ruiz Street are __________. 5. Malvar Street and Rizal Street are_________.

LUNA STREET

RIZAL STREET

LOPEZ STREET LU

IZ S

TR

EE

T

MA

LV

AR

ST

RE

ET

RU

IZ S

TR

EE

T

4

C. Draw 5 perpendicular lines

5 parallel lines 5 intersecting lines

V. Assignment

Cut pictures from old magazines or newspapers. Mark the parallel, intersecting and perpendicular lines. Paste them on a bond paper and label them.

Identifying Perpendicular, Parallel and Intersecting Lines


Cognitive: Identify perpendicular, parallel and intersecting lines Psychomotor: Illustrate/show perpendicular, parallel and intersecting line through various

games Affective: Show sportsmanship during games

II. Learning Content Skill: Identifying perpendicular, parallel and intersecting lines Reference: BEC PELC III A 1.2 Material: road map Value: Sportsmanship

III. Learning Activities


1. Drill Color all the squares red.

Cross out all the circles. Connect all the letter A.

What lines are formed?

5

2. Review Match column A with column B 1. lines that intersect with each

other and form a square corner 2. lines that do not meet 3. lines that cross each other

a. parallel lines b. intersecting lines c. perpendicular lines

3. Motivation

Who among you have gone to cities like Manila? What can you say about the roads in Manila?


1. Presentation

a. Marian is a tourist guide. She takes Japanese tourist to different places in Metro Manila,

passing through EDSA.

Can you see intersections on the map? Can you see straight roads? Can you see roads that meet?

b. Roads can represent lines. There are lines that do not meet or cross even if both ends are extended. There are also lines that meet at a common point. Look at the different lines again.

c. Lead the pupils to identify the lines. d. Give other examples.

6

Look at the illustration below.

Ask: What pair of avenues are parallel? What pair of avenues intersects? What pair of avenues do not intersect and are not parallel?

2. Guided Practice Game: The boat is sinking (instead of grouping yourselves into two or three …. Use statements like “form intersecting lines, parallel lines and perpendicular lines”. Bring me a handkerchief with parallel lines, etc. In games, we either win or loose. What attitude should you show? If you win, would you boast? Why? If you lose would you be angry? Why?

3. Generalization

What are perpendicular lines? parallel lines? intersecting lines?

Perpendicular lines intersect each other and form square corners. Parallel lines are lines that do not meet. Intersecting lines are lines that cross each other at a single point.

C. Application

Identify all the perpendicular, parallel, and intersecting lines you see from the figure below. Write the answers in symbols: Parallel Lines: Intersecting Lines: Perpendicular Lines:

3

7 6

2

5 4

1

7

IV. Evaluation A. Write P for perpendicular, PL for parallel and IL for intersecting lines.

1. 2.

3. 4.

5. 6.

7. 8.

9. 10.

8

B. List all perpendicular lines, parallel lines and intersecting lines shown in this figure. Write in symbol.

Parallel Lines Perpendicular Lines Intersecting Lines

V. Assignment

A. Given below are lines. Identify all the perpendicular, parallel, and intersecting lines that you can see. Write the answer using symbols.

Parallel Lines: Intersecting Lines: Perpendicular Lines:

B. Make cut outs of perpendicular, parallel, and intersecting lines.

D

B A C

E

G F

H I

J

A B C

E

D

G F

H

I

J

9

Visualizing Congruent Line Segments


Cognitive: Visualize congruent line segments Psychomotor: Draw congruent line segments Affective: Appreciate the uniqueness of an object or a person

II. Learning Content Skill: Visualizing congruent line segments Reference: BEC PELC III 2.1 Materials: cut-outs of squares, circles and triangles, objects of the same length Value: Uniqueness of an object or a person

III. Learning Experiences


1. Drill

Give each pupil cut-outs of squares, circles and triangles. Ask them to form perpendicular, parallel and intersecting lines by pasting the cut-outs on manila paper.

2. Review

Study the drawing and tell whether the statements are true or false.

1. Line AB is parallel to line BG. 2. Line BD is perpendicular to line AB. 3. Line CH intersect line AB and FG. 4. Line AF is perpendicular to line EG. 5. Line DB is perpendicular to line EG.

3. Motivation

Show objects of the same length. What can you say about their length? Are all things

here on earth have the same length? God did not create things of the same length. He created things differently. What do you think is the reason?

D

E

A

F

B

G H

C

10


1. Presentation

a. The teacher draws line segments having the same length

Let the pupils measure the line segments with the use of a string and ruler.

b. What can you say about the two line segments? Do they have the same length? What is the other word for “the same length”? How do we write “line segment CD is congruent to line segment EF” in symbol?

CD EF

c. Show a rectangle.

d. Using the ruler, ask a pupil to measure the sides of the rectangle. Which segments are of the same length?

2. Guided Practice

a. Game

Give each pupil a stick. Have them look for the stick of the same length as theirs. a. Divide the class into 3 groups. Give group A string, group B, cartolina strips and group C

sticks. Ask them to make pairs of congruent line segments using the materials given to them.

3. Generalization

How do we know if line segments are congruent? When are line segments congruent? Line segments are congruent if they have the same length and measurement.

C. Application

A. Using a ruler, make line segments congruent to the line segments in each number.

1.

2.

3.

4.

C D

F E

J R

C A

A B

X Y

10cm

15cm

5cm V U

20cm L M

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5.

B. Answer the following. ( Pair Share)

1. Name all the line segments you can find in the figure.

2. How many line segments can you see in the figure?

IV. Evaluation

A. Connect all points from A to S then back to A. Be sure not to make curve lines. List down at least 10 combinations of congruent line segments.

10

9

8

7

6

5

4

3

2

1

0 1 2 3 4 5 6 7 8 9 10

D

E FG

H

JI

K

LMO

N

P

Q

R

S

A

B

C

7cm X W

B

O C A

D

C

A

B D

E F

12

B. Get your ruler and pencil. Draw congruent line segments with the following measurements. 1. 10 cm 2. 15 cm 3. 20 cm 4. 25 cm 5. 30 cm

C. Look at the line. List down 10 pairs of congruent line segments.

A B C D E F G H

V. Assignment

List down things in your house which show congruent line segments.

Identifying Congruent Line Segments


Cognitive: Identify congruent line segments Psychomotor: Draw/measure congruent line segments Affective: Show neatness in the different activities

II. Learning Content Skill: Identifying congruent line segments Reference: BEC PELC III-A 2.2 Materials: textbooks, cut-outs of different polygons, grid, ruler Value: Neatness



1. Drill (flash card)

Stamp your feet if the figure shown are parallel lines, clap your hands twice if intersecting and say yes if perpendicular.

2. Review Look at the figure below then complete the statement.

AB ___

A

B C

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WY ___

WX ___

BC ___

AB ___

3. Motivation

Show congruent shapes like squares, circle, triangle, and the like. Ask questions about the shapes. Ask: If you will choose a shape, what will you choose? Why?


1. Presentation

a. Present a regular decagon.

Ask: What kind of figure is this? How many line segments are found in this figure? Ask the pupils to give the line segments that can be found in the figure.

b. Ask the pupils to measure the line segments? Are they congruent? Lead the students in making combinations like.

AB BC EF GH

CD DE IJ JK

c. Show another example.

Which line segments are congruent?

W X

Z Y

J

E

I H

G

F

6 cm 5 cm

5 cm 6 cm

5 cm

5 cm

D C

B

A

E

A

J

B

C D

E

F

G

H I

14

2. Guided Practice

a. Working in triads. (Do not ask the pupils about the name of each shape.)

Give each group a ruler and cutouts of either triangle, rhombus, parallelogram, trapezoid, heptagon, octagon, or nonagon. Follow the steps.

1. measure each side of the polygon 2. name all the line segments 3. name the congruent line segments.

b. Work in Dyads

List all the congruent line segments. Anybody who listed the most number of congruent

line segments will receive a prize.

3. Generalization

How do we identify congruent line segments? What do you call line segments with the same length?

Line segments with the same length and measure are called congruent line segments.

C. Application

Draw pairs of congruent line segments with the following measurements.

1. 15cm 2. 25cm 3. 20cm 4. 17cm 5. 12cm

IV. Evaluation

(Prepare five crayons of different colors)

A. Look at the grid. Color the congruent lines. Use only one color for each pair. Ask: What should you observe in coloring this grid? Why? (Neatness)

A F

D

E

C G B

15

B. Are the two line segments congruent? Measure them using your ruler. Write yes or no.

1) 2.

3. 4.

5.

V. Assignment

Use your ruler. Construct the following: 1. Line segments GH and IJ with 7 cm length. 2. Line segments KL, MN, LN, KM with 6 cm length. Form them into a square. 3. Line segments TS, SP and PT with 4 cm length. Form them into an equilateral triangle. 4. Line segments AB BC CD DE EF and FA with 3 cm length. Form them into a regular

hexagon. (a 6-sided figure) 5. Line segments BC, CF, FH, HI, IJ with 5 cm length. Form them into a regular pentagon. (a 5-

sided figure).

TURNS


Cognitive: Visualize the turn of figures Psychomotor: Create a simple reflection by turning given figures Affective: Work harmoniously in a group

16

II. Learning Content

Skill: Visualizing turn of figures Reference: BEC – PELC III. A. 3A Materials: cut-outs of figures, isometric paper, centimetre dot paper, crayon, ruler Value: Working harmoniously with the group



1. Drill Ask the pupils to stand up then give commands like right turn or left turn.


1. Presentation

A. Divide the class into two. Give each group cutout of figures.

Mechanics: a. Create shapes that look like person, place, animal, or thing by using all of the

given figures. b. Paste on a cartolina the shapes that you formed. c. Publish your work.

B. On the chalkboard, pin the triangle and trace it.

The new position shows the turn of the image. The point that is pinned is the turn center.

Ask: What movement is shown by the figure?

How is it like the original triangle? Are they congruent?

Move the triangle to the right and trace it again.

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a. Present these figures

Ask: Which of the drawings show turns? Call the pupils to show more turns of the drawings.

2. Guided Practice

a. Divide the class into five groups. Give each group a figure and dot paper. Let them copy the figures in the dot paper and draw turns.

Examples:

Have them compare their drawings with other groups. How are they the same? How are they different? How did you work with your group? What happens if you cooperate with your group? Do you also do this at home or in your barangay? In what way?

3. Generalization

What is a turn? To which direction will it turn? How do we visualize the turn of figures?

Turn is a clockwise or counterclockwise movement of figures.

C. Application

A. Identify the drawings that show turns. Explain your answer.

2.

3.

1.

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B. How many turns does each triangle make?

IV. Evaluation

Choose the correct figures that show turn images of the shaded figure.

V. Assignment

Find in your kitchen 5 examples of images that show turns of figures. List them.

5.

4.

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FLIPS


Cognitive: Identify flip Psychomotor: Create simple tessellation using flip Affective: Return things to their proper places


Skill: Visualizing flip Reference: BEC – PELC III.A.3.1 Materials: mirror, cutouts Value: Orderliness



1. Drill

Group the pupils into two. Have them look at the alphabet and number charts. Let them find the letters and numbers that have line of symmetry. The group with more correct answers wins the game.

2. Review (Working in triads)

Which of the following figures create tessellations?

IV.

3. Motivation

Show a mirror. When you face a mirror, what do you see? Is that your real self? What do you call that?


1. Presentation

a. Present the situation.

20

Lanny and Chris are experimenting with mirrors. They looked at the mirror image of a figure.

Show to the class the figure they used.

Ask: What figure did Lanny and Chris use? What do you call the figure that appeared on the mirror?

(The mirror image is called the Flip image.)

b. Group Activities Activity 1

Divide the pupils into 5 groups. Give each group a mirror and cutouts of letters/ figures. Have them find where to

place the mirror and the cutouts to show a flip. After a while let each group present their image and find out if it shows a flip.

Ask: How are the cutouts alike? How are they different? Are the figure and its flip congruent? Explain.

Activity 2

Have each group look for 5 sets of objects that flip. Let them arrange the objects in such a way that they show a flip. Let them explain their work.

Example:

Let them change the position of the objects so that it won’t show a flip. Example:

What did you do with the objects that you used in your activity?

21

Why do you have to return those objects to their proper places?

Do you do this at home?

What did you do? How about your sisters and brothers?

2. Guided Practice

a. Working in fours (Pair Square)

Give each group 2 cutouts of letters/numbers. Have them paste one letter/number on one side of the bond paper. Let them flip the other and paste it down.

Examples:

b. Working in groups ( 5 in each group)

Copy the figure into the dot papers, and make several cutouts. Use cutouts to show the mirror images. The dotted line shows where the mirror is.

Etc.

3. Generalization

Why is a mirror image called a flip image? What is a flip? How can we identify a flip image?

22

A flip is a reflection of an object wherein size and shape do not change.

C. Application

Which of these pictures show a flip? Explain your answer.

1. 2. 3. 4. 5. 6.

IV. Evaluation

A. Copy each of the following in the dot papers. Draw the flip image.

1. 2. 3. 4. 5.

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

23

B. Explain how you got your answer.

V. Assignment

List down 5 objects that show flip. Locate them inside your houses or in the playground.

SLIDES


Cognitive: Visualize slides Psychomotor: Create simple slides Affective: Follow the standards for ones safety


Skill: Visualizing slides Reference: BEC – PELC III A.3C Materials: dot paper, cutouts Value: Following standards



1. Drill

Which figures are congruent?

2. Review

Do “yes clap” if the figure shows flip, “no clap “ if not.

24

(Yes clap – clap 3x, stamp right foot 3x, then raise right hand then shout Yes.)

3. Motivation Show a picture of a slide. Ask. What is this? Who usually use this? Show the picture of the child in the slide.

What do you notice about the position of the boy from the original to its image? Did he change position?


1. Presentation

25

a. Present the cutouts of the following figures.

Ask: Does the first triangle in Figure A change its size and shape when it moved

down? How about its position?

Call a child to match the triangle.

Do the same with figures B and C. Did the position of each figure change? Look at the line. This is called the slide line.

b. Present these figures

You can see a repeating pattern. If you trace a part of the pattern and slide it, will the tracing match the pattern farther along? Will the tracing match no matter what distance you slide it?

2. Guided Practice

a. Group the class into 4. Ask them to go outside and look for patterns that show slides. Set standards before the pupils go out. Why do we have to set standards before doing an activity outside the room? Where else do we set standards? Do you follow the standards set by your parents? Have pupils cite examples. Let each group report what they have found.

b. Work in pairs

Give each pair cutouts of figures.

26

Let them arrange the figures in such a way that it will show slides.

Examples:

3. Generalization How do we visualize slides of a figure? What is a slide? What will happen to the original figure if we slide it? Slide is a movement of figures or objects without changing the position.

C. Application

Will the slide image match the original? Why? Draw the slide image.

27

IV. Evaluation

Draw the slide image for the given figures.

V. Assignment

Draw 5 figures and draw its slide image for the given slide arrow.

Forming Simple Symmetrical Designs


Cognitive: Form simple symmetrical designs out of given shapes Psychomotor: Draw/create/cut simple symmetrical designs Affective: Practice creativity in one’s work


Skill: Forming simple symmetrical designs Reference: BEC PELC III.A.4 Materials: textbooks, cartolina, pair of scissors, crayon, samples of symmetrical designs,

picture showing summer time Value: Creativity



1. Drill

28

Match column A with column B.

1. a. perpendicular lines

2. b. intersecting lines

3. c. parallel lines

2. Review

Trace each picture and draw the other side.

1.

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

2.

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

29

3.

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

• • • • • • •

3. Motivation Show several pictures showing summer time. Ask questions like: What game do little

boys love to play during summer time? Do you know why kites can fly? One reason the kite can fly is that it is symmetrical. Do you know the meaning of symmetrical? You’ll know that during our lesson.


1. Presentation

a. Present cut-outs of the following.

b. Fold each figure as many as long as each half is symmetrical to one another. Lead the child in counting the folds you’ve made. Draw dotted lines along the fold. Let them compare the two halves. Ask: Are they the same? Do they match exactly?

c. Present another set of cut-outs. (This time use design other than geometrical figures.

Repeat procedure b.

30

d. This time the teacher gets blank square sheets. Demonstrate how to make simple symmetrical designs. (Reminder: Show first to the class the designs before cutting.)

Procedure: 1. Fold a piece of paper. 2. Draw a shape along the fold. 3. Cut-out the shape and unfold it.

2. Guided Practice

a. Group the class into four. Provide each group an activity envelope which contains different kinds of figures. Instruct them to follow the direction. Group 1

Color the figures that show symmetry.

Group 2

If you fold each one into two, which will have symmetry? Draw a dotted line to help you.

31

Group 3

How many lines of symmetry does each figure have? Draw them.

32

Group 4 Color the shape that has symmetry.

b. Working in dyads Group pupils in pairs. Ask: In doing your activity what should you remember? To

make your work more beautiful, what should you show? Where else can you show your creativity? Do you know who among your classmates/friends are known for their creativity? In what aspect?

1. Get a piece of paper. 2. Fold it. 3. Draw a shape along the fold. 4. Cutout the shape

3. Generalization

What do you call the broken line that we draw when we match the halves of the figure?

Line of symmetry. When are figures symmetrical? Figures are symmetrical when they match exactly when

folded together in halves.

C. Application

A. Make symmetrical figures by drawing the other half.

1. 2. 3.

4. 5.

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B. Is the dotted line a line of symmetry? Explain your answer.

IV. Evaluation

A. These figures have more than one line of symmetry. Trace each figure then draw the lines of symmetry.

1. 2. 3.

4. 5.

B. Draw half of a picture on grid paper. Exchange papers with your classmate. Each of you draw the other half of the picture so the complete picture has symmetry. Return the pictures. Ask: Did they draw the other half exactly?

3.

2.

1.

5.

4.

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V. Assignment

A. Draw the other half of the figures below.

B. Draw several figures that have symmetry. Write few sentences to explain why they are symmetrical.