CHAPTER i (dangsua)x

CHAPTER I- PERPENDICULAR LINES PARALLEL LINES.
Date of teaching:
PERIOD 1: VERTICAL ANGLES
A. OBJECTIVES.
1. Knowledge: Students know the properties of vertical angles.
2. Skill: Train skill doing exercises about: skill drawing figure.
3. Education: Education about carefully, precisely in learning for students
B. PREPARATIONS.
- Teacher: Straight ruler, protractor.
- Students: Straight ruler, protractor.
C. PROCESS ORGANIZATION OF TEACHING.
I. Organize.
7C:
II. Check your homeworks.
III. Teaching and learning new lesson.
TEACHER’ S AND STUDENTS’
ACTIVITIES

CONTENTS

Activity 1. What are Vertical Angles?
Introduce the chapter I geometry 7.
Observe figure 1 page 81:
T: two angles O1 and O3 are called vertical angles.
T: Comment on the relationship of side of Ô1 and Ô3.
S: answer


T: . What are Vertical Angles?
S read definition .
S do ?2, T comment.

1. What are Vertical Angles?
x
x’
y’
y
1

2
3
4

O

-Two angles O1 and O3 are called vertical angles.
-Vertical angles are two angles such that each side of this angles is an opposite ray
of the side of that angles.

Activity 2. Properties of Vertical Angles.
S do ?3: Observe figure 1 and
a) Measure angles Ô1 and Ô3 .
Compare their measurements.
b) Measure angles Ô2 and Ô4 .
Compare their measurements.
c) Predict results drawn from the
question a) and b)
Practice reaoning:
Ô1 + Ô3 =? ;

2. Properties of Vertical Angles

Results a) Ô1 = Ô3
b) Ô2 = Ô4
c) Two vertical angles are
congruent.


Ô2 + Ô3 = ?
It follows that Ô1 = Ô3
We have the following property

Two vertical angles are congruent.

IV. Consolidation:
Read text book about property
Do exercises 1 and 2 in the textbook.
V. Guide home:
- Learn about the definition and property of vertical angles.
-Do exercises 3-10 in the textbook.
-Do exercise in the workbook.


Date of teaching:
PERIOD 2: PRACTICE
A. OBJECTIVES.
1. Knowledge: Students know the properties of vertical angles and use do
exercises.
2. Skill: Train skill doing exercises about: skill drawing figure.
3. Education: Education about carefully, precisely in learning for students
B. PREPARATIONS.
- Teacher: Straight ruler, protractor.

- Students: Straight ruler, protractor.
C. PROCESS ORGANIZATION OF TEACHING.
I. Organize.
7C:
II. Check your homeworks.
III. Teaching and learning new lesson.
TEACHER’ S AND STUDENTS’
ACTIVITIES

CONTENTS

Activity 1. Review
- Student 1: recalled the definition and property of vertical angles and draw to
illustrate.
- Student 2: do exercises 4 in the textbook.
Activity 2. Practice.
Exercise 6 page 83.
- Students read problem and how to draw figure.
O
x
x’
y
y’
470


S: Work in pair to finish the task in 3 minutes
How can you comment about exercise 7?
The students comment.

Student work in groups and answer.

Students read problem
Teacher hints students to draw figure
T: Name two right angles not vertically opposite.
Student work in groups and answer.


Student work in groups and answer.
T: How do we fold the paper to show that two vertical angles are congruent?
Exercise 6 page 83
+ Method:
- Draw angle xOy = 470.
- Draw two opposite ray of Ox and Oy.
- Angle x’Oy’ is vertically opposite to angle xOy and congruent 470.
We have:
Ô1 = Ô3 = 470 (vertical angles)
Ô1 + Ô2 = 1800 (adjacent-supplementary angles)
Hence Ô2 = 1800 – 470 =1330
Ô4 = Ô2 = 1330 (vertical angles)
Exercise 7 page 83
O
x’
x
y’
z’
z
y
1
2

3
4
5
6

Pairs of congruent angles are :


µ =O
¶ ;O
¶ =O
µ ;O
µ =O
¶
O
1
4
2
5
3
6
·
·
· ' = z· ' Oy
xOz
= x· ' Oz ';yOx'
= y· 'Ox; zOy
· ' = zOz
· ' = 1800
x· Ox' = yOy

Exercise 8 page 83
Worksheet to the student.
Exercise 9 page 83
y
A
x
x’
y’

· y and yAx'
·
xA
·
·
yAx'
and x'Ay'
·y 'Ax' and y'Ax
·
·
· y
y'Ax
and xA
Exercise 10 page 83

IV. Consolidation:
Read text book about property of vertical angles.
V. Guide home:
- Learn about the definition and property of vertical angles.
-Do exercises 4-5 in the workbook.

Date of teaching:
PERIOD 3: TWO PERPENDICULAR LINES
A. OBJECTIVES.
1. Knowledge: Students know the two perpendicular lines and denoted by ⊥.
Students know the property : There is one and only one a’ passing through O
and perpendicular to given line a.
2. Skill: Train skill doing exercises about: skill drawing figure.
3. Education: Education about carefully, precisely in learning for students
B. PREPARATIONS.
- Teacher: Straight ruler, protractor.
- Students: Straight ruler, protractor.
C. PROCESS ORGANIZATION OF TEACHING.
I. Organize.
7C:
II. Check your homeworks.
III. Teaching and learning new lesson.
TEACHER’ S AND STUDENTS’
ACTIVITIES

CONTENTS

Activity 1. What are two perpendicular lines?
S do ?1 and ?2
Teacher hints students to practice reasoning:
Using a linear pair of angles or two vertical angles.


T: . What are two perpendicular lines?

S read definition .
T: We have the definition

x
x’
y’
y
O

When two lines xx’ and yy’ intersect so that one the angles formed is a right angle,
the lines are called two perpendicular lines and denoted by
xx’⊥yy’.
Activity 2. How to draw two perpendicular lines.
S do ?3 and ?4.
T comment.
T introduce some drawing ways are
illustrated in figure 5 and 6 in textbook,
page 85.
T: We accept the following property.

*There is one and only one a’ passing
through O and perpendicular to given


line a.
Exercise 11 page 86:
Fill in the blanks in the following
statements:
a) Two perpendicular lines are …
b) Two perpendicular lines a and a’ are

denoted by ….
c) Given a point A and a line d. …..line
d’ passing through A and perpendicular
to line d.

Activity 3. Perpendicular bisector of a segment.
I
A
B
x
Look at figure 7, we recognize that:
I is the midpoint of segment AB. Line
xy is perpendicular to the line AB at I.
We say: The line xy is the perpendicular
bisector of the segment AB.
What is perpendicular bisector of a
segment?
S read definition .

-The line perpendicular to a segment at
its midpoint is called the perpendicular
bisector of that segment.

When xy is the perpendicular bisector of
the segment AB, it is also said that A is
the reflected image of B in line xy or B
is the reflected imabe of A in line xy.

IV. Consolidation:
- Recall of two perpendicular and perpendicular bisector of a segment.

I
C
D
d
- S do exercise 14 page 86 in the textbook.

V. Guide home:
- Learn about the definition and property of perpendicular and perpendicular
bisector of a segment.
-Do exercises 12, 13, 14-18 in the textbook.
------------------------------------------------------------------------------


Date of teaching:
PERIOD 4: PRACTICE
A. OBJECTIVES.
1. Knowledge: Students know explaining two perpendicular lines and use do
exercises.
2. Skill: Train skill draw two perpendicular lines and perpendicular bisector
of a segment.
3. Education: Education about carefully, precisely in learning for students
B. PREPARATIONS.
- Teacher: Straight ruler, protractor.
- Students: Straight ruler, protractor.
C. PROCESS ORGANIZATION OF TEACHING.
I. Organize.
7C:
II. Check your homeworks.

S1: What are two perpendicular lines
and drawing illustrate?
S2: What is perpendicular bisector of a
segments and draw perpendicular
bisector of segment AB=4cm?
S come out to board.
T comment and give point.
III. Teaching and learning new lesson.
TEACHER’ S AND STUDENTS’
ACTIVITIES

CONTENTS


S read problem.
S do exercises 15 and give the conclusions
T: Draw image in a way expressed in the following words:
·
xOy
= 450
- Draw
Take any point A in xOy angle.
1
2
Draw line d through A and perpendicular to the ray Ox at B. Draw line d
through A and perpendicular to the ray Oy at C.
S come out to board and worksheet.

Redeaw figure 11 and show clearly the drawing steps.
Observe figure 11 and answer.

S work in group.

S read problem and do
T: Draw in two cases: three points A, B, C are collinear and three point A, B, C are
not collinear.
Exercise 15 page 86:
+ zt ⊥ xy at O.
+ There are 4 right angles:
Exercise 18 page 87:

O

· , zOy
· , yOt
· , t·Ox
xOz


A
C
B
d1
d2
x
y

450

Exercise 19 page 87:
600

O
A
B
C
d1
d2

Exercise 20 page 87:

IV. Consolidation:
- Recall of two perpendicular and perpendicular bisector of a segment.
V. Guide home:


- Learn about the definition and property of perpendicular and perpendicular
bisector of a segment.
-Do exercise in the workbook.
-----------------------------------------------------------------------------Date of teaching:
PERIOD 5: ANGLES FORMED BY ONE LINE CUTTING TWO OTHERS
A. OBJECTIVES.
1. Knowledge: Students know alternate interior angles and corresponding
angles.
Students know the property : If line c cuts two lines a and b and of the angles
formed there are a pair of alternate interior angles whose measurement are equal,
then :
- Two remaining alternate interior angles are congruent.
- Two corresponding angles are congruent.
2. Skill: Train skill doing exercises about: skill drawing figure.
3. Education: Education about carefully, precisely in learning for students
B. PREPARATIONS.

- Teacher: Straight ruler, protractor.
- Students: Straight ruler, protractor.
C. PROCESS ORGANIZATION OF TEACHING.
I. Organize.
7C:
II. Check your homeworks.
III. Teaching and learning new lesson.
TEACHER’ S AND STUDENTS’
ACTIVITIES

CONTENTS

Activity 1. Alternate interior angles. Corresponding angles.


S come out to board.
+Draw two lines a and b.
+ Draw line c cuts two lines a and b at A and B.
T introduce about alternate interior angles and corresponding angles.

S do ?1
S come out to board and worksheet.
T comment.

S do exercises 21 page 89.
Observe figure 14 and fill in the blank(…) in the followings.
P
O
R
N

T
I


A
B
a
b
c
1

2
3
4
4
3
2
1

-Two angles A1 and B3 , as A4 and B2 are called alternate interior angles.
-Two angles A1 and B1 , A2 and B2 , A3 and B3 , A4 and B4 ,are called corresponding
angles.
4

x
y


z
t

u
v
A
B
1
1
2
2
3
3
4

?1

Exercises 21;
·
·
IPO
and POR
are pair of.....
a)
·
·
OPI
and TNO
are pair of....
b)
·
·
PIO

and NTO
are pair of.....
c)
·
·
OPR
and POI
are pair of.....
d)

Activity 2. Property.
Observe figure 13 in the textbook.
S do ?2


Hint:
a) Using linear pair of angles
b) Using vertical angles
S come out to board worksheet
T comment.

We have the following properties:

S reading and writing properties.

?2
4

A
B

c
a
b
1


1
2
2
3
3
4

¶ and A
¶ are linear pair
a) We have: A
4
1
¶ = 1800 − A
¶ = 1800 − 450 = 1350
⇒A
1

4

Similarly :B¶ 3 = 1800 − B¶ 2 = 1800 − 450 = 1350
¶ =A
¶ = 1350
⇒B
3

1

¶ =A
¶ = 450 (vertical angles)
b )A
2
4
⇒ B¶ 4 = B¶ 2 = 450 (vertical angles)

c )Three remaining pairs of corresponding
angles and their measurements are :
¶ =B
µ = 1350
A
1

1

¶ = B¶ = 1350
A
3
3
¶ = B¶ = 450
A
4

4

*If line c cuts two lines a and b and of the angles formed there are a pair of

alternate interior angles whose measurement are equal, then :
- Two remaining alternate interior angles are congruent.
- Two corresponding angles are congruent.

IV. Consolidation:
- Recalling of alternate interior angles, corresponding angles.


- S do exercise 22 page 89 in the textbook.
V. Guide home:
- Learn about alternate interior angles, corresponding angles.
-Do exercise 23 in the textbook and exercises 16-20 in the workbook.
----------------------------------------------------------------------------Date of teaching:
PERIOD 6: TWO PARALLEL LINES
A. OBJECTIVES.
1. Knowledge: Students know rules to identify two parallel lines.
Students know drawing two parallel lines.
2. Skill: skill drawing two parallel lines.
3. Education: Education about carefully, precisely in learning for students
B. PREPARATIONS.
- Teacher: Straight ruler, set square.
- Students: Straight ruler, set square.
C. PROCESS ORGANIZATION OF TEACHING.
I. Organize.
7C:
II. Check your homeworks.
Question: What are two parallel lines?
III. Teaching and learning new lesson.

TEACHER’ S AND STUDENTS’

ACTIVITIES

CONTENTS


Activity 1. Recalling knowledge in grade 6.
S read textbook, page 90.
b
a
T recall knowledge in grade 6.

1. Recalling knowledge in grade 6.
- Two parallel lines are two that have no
point in common.
-Two distinct lines either intersect or are
parallel.

Activity 2. Rules to identify two parallel lines.
2. Rules to identify two parallel lines: ?
S do ?1 in the textbook.
1
Observe figure 17 (a, b, c). Guess which
a) Lines a and b are parallel.
lines are parallel to each other.
b) Line d is not parallel to line e.
S worksheet and answer teacher’s
c) Line m is parallel to line n.
questions.
T comment.
We accept the following property:

*Property: In the textbook, page 90.
S reading and writing properties.
-Two parallel lines a and b are denoted
by a//b.
When lines a and b are parallel, we also
say: lines a is parallel to b, or line b is
parallel to line a.

Activity 3. Drawing two parallel lines.
3. Drawing parallel lines.
S read problem ?2.
S observe figure 18 and 19 in the
textbook, page 91and then T introduce
some ways of drawing are illustrated in
figure 18, 19.
S drawing two parallel again.


IV. Consolidation:
- Recalling rules to identify two parallel lines.
- S do exercises 24 page 91 in the textbook.
V. Guide home:
- Learn about two parallel lines.
-Do exercise 25-27 in the textbook and exercises 21-24 in the workbook.
----------------------------------------------------------------------------Date of teaching:
PERIOD 7: PRACTICE
A. OBJECTIVES.
1. Knowledge: Students know rules to identify two parallel lines.
Students know drawing two parallel lines.
2. Skill: skill drawing two parallel lines.

3. Education: Education about carefully, precisely in learning for students
B. PREPARATIONS.
- Teacher: Straight ruler, set square.
- Students: Straight ruler, set square.
C. PROCESS ORGANIZATION OF TEACHING.
I. Organize.
7C:
II. Check your homeworks.
Question: What are rules identify two parallel lines? And drawing
illustrated.
S come out to board answer teacher’s question.


III. Teaching and learning new lesson.
TEACHER’ S AND STUDENTS’
ACTIVITIES

CONTENTS

Exercise 26 page 91:
S read problem.
S come out to board to drawing.
Who can you do this exercises?
S answer, T comment.

Exercise 27 page 91:
S read problem.
S come out to board to drawing.
Who can you do this exercises?
S answer, T comment ?

S worksheet.
T says: the point D can coincide point D’.
Exercise 28 page 91:
S read problem.
S work in group and then worksheet.
T hint: Using 600 angle of set square to draw equal alternate interior angles (or
corresponding angles).
T comment.