cho A1,A2,A3,...,A100 trong do khong co 3 diem nao thang hang. goi S la tong cac doan thang nhan hai diem trong cac diem do lam dau mut. Hay so sanh S voi 5000
cho 2012 duong thang trong ko co 2 duong thang nao song song va ko co 3 duong thang nao dong quy .tinh so giao diem cua duong thang ay
tren duong thang a lay 3 diem A ,B ,C phan biet so duong thang co tat ca
tren duong thang d cho 3 diem A,B,C sao cho AB=6cm,AC=4cm.a,tinh do dai BC .b,1 diem O nam ngoai duong thang d sao cho goc AOB=70 do ,goc AOC=30 do .tinh BOC
tren duong thang b lay 3 diem A , B ,C . biet AB = 8 cm , BC = 4 cm . goi M ,N ,P lan luot la trung diem cua cac doan thang AB , AC , BC , chung to rang cac doan thang MN va AP co cung trung diem
Cho 3 diem thang hang A,B,C sao cho B nam giua A va C.Lam the nao de chi do 2 lan,ma biet duoc do dai cua 3 doan thang AB,BC,AC?hay neu cac cach lam khac nhau.
Giúp mk nha mk cần gấp!!!!!
ve hinh theo cach dien dat sau:
-cho 3 diem A,B,C khong thang hang
-ve hai tia ab,ac
-ve ay la tia doi cua tia ac
-lay i la trung diem cua doan thang bc
Bai1:cho tia Ox , tren tia Ox ve diem M va N sao cho OM=6cm ; ON=8cm
a)Tinh MN
b)Goi I la trung diem cua ON .Tinh IM
Bai 2. Tren duong thang xy ve doan AB =4cm sau do lay diem C sao cho AC=3cm .
Tinh CB
cho ab =12cm .goi c la trung diem cua ab.tinh ac cb? lay 2 diem de tren doan thang ab sao cho ab=be=5cm tinh cd ce? diem c co la trung diem cua doan de khong ?vi sao