dien vao cho trong cac phat bieu sau :

a)Bat ki duong thang nao nam tren mat phang cung la bo chung cua hai .........

b)cho 3 diem khong thang hang  O,B,A .Tia  Ox  nam giua hai tia OA , OB khi tia Ox cat ......

cho ba diem ko thang hang O A B.tia Oxnam giua hai tia OA,OB khi tia Ox cat.............

dien vao o trong

Cho ba diem khong thang hangO,A,B. Tia Ox nam giua hai tia OA,OB Khi tia Ox cat ...

bai 1;cho 2 tia Ox vaOy khong doi nhau

a,ve duong thang aa' cat tia Ox va Oy lan luot tai A va B khac O.Ve diem M nam giua A va B.Ve tia OM.Ve tia ON la tia doi cua tia OM

b,chi ra nhung doan thang tren hinh

c,chi ra 3 diem thang hang tren hinh

bai 2;ve tia Ox.Ve tren tia Ox voi OA la 3cm;OB la 5cm;OC la 7cm

CMR diem B la trung diem doan thang AC 

tren tia ox cho doan thang oa=4cm; ob = 2cm hoi a) trong ba diem o;a;b thi dien nao nam giua hai diem con lai b)chung to diem b la trung dien cua doan thang oa c) ve tia oy la tia doi cua tia ox tren tia oy lay dien c sao cho oc =3 so sanh bc va oa d) goi diem d la trung diem cua doan thang oc tinh do dai doan thang bd

Trên tia ox lay 2 diem A va B sao cho OA =3,5 cm,OB=7 cm Trong 3 diem O,A,B diem nao nam giua 2 diem con lai .Vi sao .Tinh AB .Diem A co phai la trung diem cua doan thang OB khong ?Vi sao? Lay diem K tren tia Ox sao cho BK =2 cm.Tinh OK

tren tia Ox lay hai diem A va B sao cho OA = 2cm, OB = 4cm:

a) Diem A co la trung diem cua doan thang OB khong? Vi sao?

b) Tren tia doi cua tia Ox lay C sao cho O la trung diem cua AC. Tinh AC, BC

c) Tren doan OB lay D sao cho OB = 4OD. Tinh BD

d) Tren tia Ox lay E sao cho OE = 7cm. B co nam giua D va E khong? Vi sao?

cho 3 diem ko thang hang o,a,b. ve tia ox nam giau oa,ob khi....

Ve tia OX , tren tia OX ve cac doan thang  OA = 2cm va doan OB = 6cm 

a) Trong 3 diem O , A,B diem nao nam giua ? Vi sao ?

b)So sanh OA va OB 

c ) Goi I la trung diem doan OB . Trong 3 diem A,O,I diem nao nam giua 2diem . V i sao? Tinh do dai AI