I- TRC NGHIM:

N TP I 7 CHNG I

I- TRC NGHIM: 1- Cho ng thng d v mt im A nm ngoi ng thng d. Qua A ta v c:

A. V s ng thng song song vi d. B. t nht mt ng thng song song vi d.

C. Nhiu nht mt ng thng song song vi d. D. Khng v c ng thng no song song vi d.

2- Hai ng thng ct nhau to thnh bao nhiu cp gc i nh:

A. 1

B. 2

C. 3

D. 4

3- Qua 1 im ngoi ng thng cho trc, ta v c bao nhiu ng thng song song vi ng thng cho trc:

a. 1

b. 2

c. 3

d. 4

4- Cho 2 ng thng m v n song song. ng thng d to vi ng thng m gc bng 30o. Gc to bi ng thng d v ng thng n l:

A. 60o

B. 160o

C. 30o

D. 120o5- Cho a // b. ng thng c vung gc vi ng thng a th:

A. c // b

B. c ( b

C. c khng ct bD. c trng vi b

6- ng thng xy l trung trc ca on thng MN khi:

A. xy i qua im I ca MN ; B. xy ( MN ; C. xy ( MN ti I v IM = IN; D. xy // MN v IM = IN

II- T LUN: Bi 1: Cho hnh v, bit BAC = 50o, ACD = 110o, CDE = 60o. Gii thch v sao AB // DE.Bi 2: Cho (ABC c = . V tia CD l tia i ca tia CA. Trn na mt phng b AC cha nh B v tia Cx // AB. Chng minh Cx l tia phn gic ca Bi 3: Cho hnh v v cc s liu v ln cc gc. Chng minh: Ax//By//Cz

Bi 4: Cho hnh v, bit Ax//Cz,

= 20o, = 42o, Ct l tia phn gic ca . Tnh s o ca

Bi 5:Cho hnh v, bit My//Ax, = 30o, = 48o, Az l tia phn gic ca Tnh s o ca

I.Trc nghm 1/ Ba ng thng ct nhau ti O. Tng s cc cp gc i nh (khng k gc bt ) lA.3 cp B. 6 cp C. 9 cp D.. 12 cp

2/ Ba ng thng xx, yy, zz cng i qua O. Gc no sau y l gc k b vi xy:

A. yx B. xy C. yz v zy D. yx v xy 3/ ) Cho 2 gc ph v x0y. V 0z, 0t ln lt l tia phn gic ca cc gc x0y, x0y. Bit gc x0y = 30 th s o gc z0x bng:

A. 60

B. 70

C. 75

D. 90

4/ Cho hai gc xy = zt nh hnh v. Pht biu no sau y l sai: t y

450 z O x A. xy v zt i nh B. xy v yz l hai gc k b C. xy v zt khng i inh D. yt = 900

5/ Gc to bi hai tia phn gic ca hai gc k b bng :

A. 1800

B. 600

C. 900

D. 450 II. T lun Bi 1 : Cho ng thng a v M ( a , N( a

a/ v ng thng b vung gc vi a ti M

b/ V ng thng c i qua N v c//a. Bi 2 :Hnh v sau y cho bit a // b , = 300 , = 400 . Tnh s o gc AOB . Ni r v sao tnh c nh vy .

B b

400

O

300 a

A

Bi 3 : Trn hnh bn, cho AD ( Ax, AD ( Dy, gc ABC = 600. Tnh s o gc

Bi 4 : Cho hnh v bit xx // yy , = 420 a) Tnh gc xAB

b) V tia phn gic ca ABy ct xx ti M, tnh gc AMB

c) V Bt l tia phn gic ca gc mBy

Chng minh BM b Bt l 2 tia i nhau.

Bi 5 : Cho hnh v, bit m // n m A

Tnh gc mAB? B

80

n 55 C

I-Trc nghim:

1) Hai ng thng xy v zt ct nhau ti im M. Ta cA) i nh vi .

C) i nh vi

B) i nh vi

D) i nh vi

2) Hai ng thng song song l hai ng thng:

A) Khng c im chung

C) C mt im chung

B) C v s im chung

D) C hai im chung3) Nu c hai ng thng:

A) Vung gc th ct nhau.

C) Ct nhau th to thnh bn gc bng nhau

B) Ct nhau th vung gc.

D) Ct nhau th to thnh bn cp gc i nh4) Gc to bi hai ng thng vung gc l:

A) Gc vung

B) Gc nhn

C) Gc t D) Gc btII/ T lun: Bi 1: Hnh v bn cho bit: a // b v = 420. Tnh ;;;

Bi 2: Hnh v sau cho bit: = 300; = 600; = 1500. Chng t: Ax // By x A

B y

Bi 3: Chng minh rng: Nu hai gc nhn xOy v xOy c Ox // Ox, Oy // O y th =

Bi 4: Cho hai ng thng xx v yy ct nhau ti A. Bit x,tnh x

EMBED Equation.3 ,x

EMBED Equation.3 Bi 5: Cho hnh v bit Ax // Cy v = 1100, = 500. Tnh ?

x A

1100

B

500

yC

Bi 6: Cho hnh v, bit = 110o .

Chng minh: Ax // Cy

Bi 7 : Cho hnh v, bit ;

a- Chng minh xy // zt

b- V tia phn gic ca ct xy ti C. Tnh .

c- V Bq l tia phn gic ca

Chng minh BC v Bq l 2 tia i nhau.Bi 8: Cho hnh v bit : Ax // Cy ; = 1300 ; = 1100 Tnh ? B

y CBi 9: Cho hnh v bit = 1500 ; = 1100; = 800 z MChng minh: Ma // Nb. B N t

Bi 10: Chng minh rng: Nu hai gc nhn x Ay v zB t c Ax // Bz, Ay // Bt th =

Bi 11: Cho hnh v, bit = 50o, = 110o, = 60o. Gii thch v sao AB // DE.

Bi 12: Hnh v bn cho bit: a // b v = 1420. Tnh ;;;

Bi 13:Hnh v sau cho bit: = 400; = 700; = 1500. Chng t: Ax // By

x A

B y

Bi 14: Cho hnh v bit : Ax // Cy ; = 1500; = 1300 Tnh ? B

y CBi 15: Cho hnh v bit = 1400; = 1100; = 700 z MChng minh: Ma // Nb. B N t

D

A

E

(

C

(

B

110o

50o

60o

120o

x

y

z

A

B

C

130o

110o

130o

20o

z

y

t

x

A

B

C

42o

30o

t

x

y

z

A

M

C

48o

A

D

C

B

x

y

x

y

y'

x'

n

m

B

A

O

B

(

C

(

E

A

y

t

120o

60o

m

n

A

B

xc

zc

O

40o

50o

90o

D

Nguyn Thanh Vinh THCS NGUYN DU

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