cho doan thang AB, C la 1 diem thuoc doan thang AB, D la trung dien cua CB biet AC=3cm AB=11cm tinh do dai doan thang DB

tren duong thang a lay 2 diem A va B sao cho AB=2cm lay diem C sao cho A la trung diem cua doan thang BC lay diem D sao cho B la trung diem cua doan thang AD a)tinh do dai doan thang CD   b) goi trung diem cua AB la M tim trung diem cua doan thang CD

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

cho doan thang AB co do dai la a.goi C la diem thuoc tia doi cua tia AB.goi M la trung diem cua doan thang AC.goi N la trung diem cua doan  thang CB.

a)vi sao A nam giua C vaB

b)vi sao NB=CB:2

c)tinh do dai doan thang MN

tren doan thang AC co do dai 12 cm ,lay diem B sao cho AB=5 cm .a, tinh do dai cua doan thang BC.b,goi M,N lan luot la trung diem cua doan thang AB ,BC . tinh do dai doan thang MN.c, lay diem D thuoc tia doi cua tia CA sao cho CD =7 cm . chung to rang diem C la trung diem cua doan thang BD

Tren doan thang AC dai 12cm lay diem B  sao cho AB = 5cm

a) Tinh do dai cua doan thang BC

b) Goi MN lan luot la trung diem cua cac doan thang AB, AC.Tinh do dai doan thang MN

c) Lay D thuoc tia doi cua tia CA sao cho CD = 7cm.CTR diem C la trung diem cua doan thang BC

cho doan thang ab=6cm diem m thuoc doan thang ab biet bm =2cm

a tinh do dai doan thang am

b tten tia doi cua tia áb lay diem d sao cho ad=4cm tinh do dai doan thangDM

c diem A co phai la trung diem cua doan thang DM

cho do dai doan thang AB dai 45 cm . tren doan AB lay 2 diem C va D sao cho C la trung diem doan AD , D la trung diem doan CB . tinh do dai doan CD

cho doan thang ab dai 45cm . tren doan ab lay 2diem  c va d sao cho c la trung diem doan ad; d la trung diem doan cb . tinh do dai cd