Toán Tiếng anh: Góc tạo bởi 2 đường thẳng cắt một đường thẳng

Week 3 
Period 5 §3. ANGELS MADE BY A TRANVERSAL 
I/ Objectives: 
- The knowledge: Student will know the concept interior angles, exterior angles, 
pairs of alternates interior angles, pairs of corresponding angles, pairs interior 
angles on the same side of the tranversal, pairs of alternate exterior angles 
- The skills: Students have ability to identify quickly interior angles, exterior 
angles, pairs of alternates interior angles, pairs of corresponding angles, pairs 
interior angles on the same side of the tranversal, pairs of alternate exterior angles. 
Students have skills presenting Math solutions in English well 
- The attitude: Students have self-discipline in learning and group activities. There 
is a dynamic, creative life 
II/ Vocabulary: 
- Interior angles: Góc nằm phía trong 
- Exterior angles: Góc nằm phía ngoài 
- Pairs of alternates interior angles: Cặp góc so le trong 
- Pairs of alternate exterior angles: Cặp góc so le ngoài 
- Pairs of corresponding angles: Cặp góc đồng vị 
- Pairs interior angles on the same side of the tranversal: Cặp góc trong cùng phía 
III/ Teaching and students aids: Book, notebook, ruler 
IV/ Content: 
 1/ Class organization: 
- Greeting 
- Checking attendance: How many students absentee on today ? 
2/ New lesson: 
Teachers activities Students activities Content 
In Fig.12 They see lines a 
and b cut by tranversal c 
at A and B. 
Introduce: Interior angles, 
Exterior angles, Pairs of 
alternates interior angles, 
Pairs of corresponding 
angles, Pairs interior 
angles on the same side of 
the tranversal, 
Pairs of alternate exterior 
angles 
Look and write 
1/ Alternates interior angles. 
Corresponding angles: 
Fig.12 
The eight angles maked have 
special names: 
+ Interior angles: 1A , 

4A ,

3B ,

2B 
+ Exterior angles: 

2A ,

3A ,

1B ,

4B 
+ Pairs of alternates interior 
angles: 4A and 

2B ; 

1A and 

3B 
+ Pairs of corresponding 
angles: 2A and 

2B ; 

1A and 

1B ; 
Draw a tranversal xy 
cutting zt at A and uv at 
B. Name the pairs of 
angles. 
Who’s can call name the 
pairs ? 
In the given Fig.13. The 
arm are 
4A = 

2B = 45
o
a/ Find 

1A , 

3B 
Hit: Note pairs of 
comlementary angles 
b/ Find 
2A , 

4B 
Hit: Note pairs vertically 
opposite angles 
c/ Find pairs of 
corresponding angles 
other. 
Give remark to student 
answers 
Who’s can say properties 
? 
Student draw 
Student present write on 
the board 
Three students represent 
write on the board 
Student repeat the 
properties 

3A and 

3B ; 

4A and 

4B 
? 1 
a/ The pairs of alternates 
interior angles: 
3A and 

1B ; 

4A and 

2B 
b/ The pairs of corresponding 
of angles: 
2A and 

2B ; 

1A and 

1B ; 

3A and 

3B ; 

4A and 

4B 
2/ Properties: 
? 1 
a) Find 
A 1 vaø B 3: 
- Because 
A 1 and A 4 are 
pairs comlementary angles 
then 
A 1 = 180
0
 – A 4 = 135
0
- Because 
B 3 and 

B 2 are pairs 
comlementary angles 
=> 
B 3 + B 2 = 180
0
=> 
B 3 = 135
0
=> 
A 1 = B 3 = 135
0
b) Find 
A 2, B 4: 
- Because 
A 2 and A 4; B 4 and 
B 2 are pairs vertically 
opposite angles 
=> 
A 2 = 45
0
; 
B 4 = B 2 = 45
0
c) Find pairs corresponding 
angles: 
A 2 = B 2 = 45
0
; 
A 1 = B 1 = 
135
0
; 
A 3 = B 3 = 135
0
; 
A 4 = 
B 4 = 45
0
Properties: If two line a and b 
cut by transversal c and each 
pairs of alternate interior are 
equal in measure then: 
a/ The pair of alternate interior 
angles other are equal in 
measure 
b/ The pair of corresponding 
angles are equal in measure 
 3/ Consolidation: 
Exercise: Who can do it ? 
 21/89: In the given Fig.14. Fill in the blanks 
a/ OIP and ORP are pair .. 
b/ 
OPI and TNO are pair.. 
c/ 
OPI and NTO are pair 
d/ 
ROP and POI are pair. 
 22/89: a/ Draw Fig. 15 again 
b/ If 
A 4 =  2B = 40
0
 then find other angles 
c/ Find 1A +  2B ;  4A +  3B 
4/ Homework: 
- Review all the lesson and exercise that we do today