a/Cho 3 diem A,A,C thang hang thi co may truong hop hinh ve?

b/Trong moi truong hop,co may diem nap giua hai diem con lai?

c/Hay noi cach ve ba diem khong thang hang.

ve hinh theo cach dien dat bang loi sau

a, ve duong thang MN

b, ve tia MN

c, diem C nam tren tia MN,co nhung kha nang nao xay ra?.Doi voi moi truong hop do hay chi ra diem

nam giua 2 diem con lai

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)

Ve 5 diem A,B,C,D sao cho 3 diem A,B,C thang hang, 3 diem B,C,D thang hang, 3 diem C,D,E khong thang hang

a) Giai thich vi sao 3 diem A,B,D thang hang

b) Tren hinh ve hay tim diem nam giua 2 diem con lai

cho 5 diem phan biet , ve dc bao nhieu duong thang di qua cac cap diem trong cac truong hop sau:

a/ ko co 3 diem nao thang hang

b/ co 3 diem thang hang

Trong moi truong hop sau , hay ve hinh va cho biet ba diem A , B , M thang hang khong ?

a , AM = 3,1 cm , MB = 2,9 cm , AB = 6 cm

b , AM = 3,1 cm , MB = 2,9 cm , AB = 5cm

1 . cho 4 diem A,B,C,D thang hang do :

 ke ten cac truong hop 1 diem nam giua 2 diem con lai .

ve : a) ba diem m,n,p thang hang .b)ba diem c,e,d thang hang sao cho diem e nam giua hai diem cvad .c)ba diem t,q,r khong thang hang

Ve hinh theo cach dien dat sau:

a, diem M nam giua hai diem A va B: diem N khong nam giua hai diem A va B (ba diem N,A,B thang hang)

b, Diem B nam giua hai diem A va N; diem M nam giua hai diem A va B