trên tia Ax lấy 2 điểm b và c sao cho ab = 3cm ac=7cm a/ tinh doan thang bc b/ lay diem D thuoc tia doi cua tia ab sao cho ad =1cm . chung to rang B la trung diem cua doan CD c/ lay 2 diem M va N lan luot la trung diem cua ab bc .tinh MN
tren doan thang AB =6cm.lay diem M sao cho AM=3cm.va C la trung diem cua MB.
A)tinh MB
B)chung minh M la trung diem cua AC.
Tren tia Ox ve 2 doan thang.OA=3cm,OB=5cm.
a)A co la trung diem cua OBko?vi sao?
b)tren tia Ox lay diem C sao cho OC =1cm.diem A co la trung diem cua BC ko?vi sao?
cho hai doan thang hang AB va BC sao cho AB=BC=5cm.Goi I la trung diem cua AC,K la mot diem sao cho B la trung diem cua AK.Hoi K va C co trung nhau khong?Tinh AK.
cho doan AB=12cm.diem M nam giua 2 diem Ava B sao cho AM = 2MB
goi N laf trung diem cua doan AM
chung minh M la trung diem cua doan NB
Ve diem P sao cho B la trung diem cua MP
Diem M co phai la trung diem cua doan AP khong. vi sao
cho 3 diem A,B,C khong thang hang
a)Ve duong thang AB, doan thang BC,tia AC.Lay dien M tren duong thang AB sao cho B,M nam cung phia so voi diem A
b)Ve tia Ax la tia doi cua tia AC.Lay diem N sao cho A la trung diem cua doan CN(ve tren cung 1 hinh)
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
cho 3 diem a b c thang hang , goi D la trung diem cua AB .tinh CD biet AB = 10cm ,BC= 4cm
lam on gip minh mai minh phai nop roi
Cho A;B; C thẳng hàng . goi diem D la trung diem cua doan thang AB,E la trung diem cua doan thang BC. chung to AC=2DE.
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