4 DIEM A B CS KHONG NAM TREN DUONG THANG a chung to rang duong thang a hoac cat ,hoac khong cat hoac cat 3 hoac cat 4 doan thang trong cac doan thang ab ac ad bc bd cd ? giup minh voi cac ban
cho mot duong thang a.neu co 4 diem A;B;C;D khong nam tren duong thang a hoi duong thang a co the cat bao nhieu doan thang trong 6 doan thang AB;AC;AD;BC;BD;CD
cho 3 diem A;B;C khong thouc duong thang a.Biet rang duong thang a khong cat cac doan thang AB;AC.Hoi duong thang a co cat doan BC KO .vI SAO
cho 4 diem A;B;C;D khong nam tren duong thang a. biet doan thang AB khong cat a doan thang BC cat a.doan thang CD khong cat a. hoi doan thang AD co cat a hay khong
Lay 3 diem khong thang hang A,B,C ve hai tia AB,AC
Ve tia Ax cat duong thang BC tai diem M nam giua B va C
Ve tia Ay cat duong thang BC tai diem N ko nam giua B,C
cho duong thang d va ba diem M,N,P bat ki.
a)neu duong thang d khong cat hai doan thang MN ma ko cat doan MP thi d co cat doan NP k?tai sao?
b)neu duong thang dcat doan thang MN ma ko cat doan thang MP thi d co cat doan thang NP ko?tai sao?
giup minh di,minh dang rat can
cho cac duong thang a,b,c .Biet a cat b tai diem A, b cat c tai diem C , a cat c tai diem B
a / chi ra cac doan thang co tren hinh ve
b/ ve tia AD a tia doi cua tia AC ,ve tia BE la tia doi cua tia BC
c/ lay diem M thuoc tia AC .ve tia AM
ve hinh cho to nha
Cho ba diem A,B,C khong thang hang ve duong thang a cat cac doan thang AB,AC va khong di qua A,B,C
a) goi ten hai nua mat phang doi nhau bo a
b) doan thang BC co cat duong thang a khong
Cho 3 duong thang a,b,c cat nhau theo 3 diem A,B,C và diem M khong nam tren duong thang a,b,c.Hãy lay cac diem D,E,F theo thu tu nam tren duong thang a,b,csao cho cac diem A,D,M;M,B,E;C,M,E thang hang