CHO DOAN THANG MN=7cm hay ve duong trung truc cua doan thang MNva neu cach ve

Ve doan thang AB dai 6cm co trung diem I ve duong trung truc cua AB roi ve duong trung truc cua BI

Cho 1 doan thang AB dai 4cm.Ve duong thang d la duonbg trung truc cua doan thang AB,lay O thuoc d.Qua O ve doan thang OC=2cm sao cho OC vuong goc voi d.Qua O ve doan OD=1cm sao cho OD vuong goc voi d.Chung minh C,O,D thang hang.D co phai la trung truc cua doan thang CD ko?Vi sao?(Mik can ve hinh va loi giai nhe,minh ve hinh ko chac chan,mong cac ban giup do)

Bai 20:Ve doan thang AB dai 2cm va doan thang BC dai 3cm roi ve duong trung truc cua moi doan thang ay (Ve hinh trong hai truong truong hop:ba diem A,B,C khong thang hang,ba diem A,B,C thang hang)

a) ve doan thang pq=10 cm . ve duong trung truc cua doan thang pq 

 tren duong trung truc cua doan thang  pq lay diem m khong thuoc pq . qua diem m ve duong thang d\\ pq

ve doan thang PQ=10cm ve duong thang trung truc cua doan thang PQ 

tren duong thang trung truc cua doan thang PQ lay diem M ko thuoc PQ .Qua diem M lay ve duong thang dsong song vo PQ

cho doan thang ab=7cm.goi i la trung diem cua a vab

a) neu cach ve

Tren tia Ax, ve diem B sao cho AB=2cm. Ve diem M sao cho B la trung diem cua AM 

a) Tinh do dai doan thang AM,BM 

b)Tren duong thang AB lay diem N sao cho BN=3cm . tinh do dai doan thang MN

ve hinh theo cach dien dat sau

ve tia Ox va Oy doi nhau

lay A nam ngoai duong thang xy, v doan thang AO

lay diem B thuoc tia Ox ( B khac O ) ve tia AB

ve K la trung diem cua doan thang OA