a/ là : xA , xB , xC , yA , yB ,yC
b/ Có : AB = BC - CA = 5 - 3 = 2cm
a/ là : xA , xB , xC , yA , yB ,yC
b/ Có : AB = BC - CA = 5 - 3 = 2cm
cho diem M thuoc duong thang xy . Ten tia Mx lay diem B sao cho MB bang 3cm , tren tia My lay diem C sao cho MC bang 2cm
a. tinh do da doan BC
b. goi O la mot diem nam ngoai duong thang BC . Ke cac doan thang OB , OC , OM . Biet goc BOC bang 90 do, goc BOM bang 60 do . Tinh goc MOC
1. Lay 4 diem A, B, C, D trong do khong co 3 diem nao thang hang. Ke cac duong thang di qua cac cap diem. Co bao nhieu duong thang tat ca? do la nhung duong thang nao?
2. Lay 4diem M,N,P,Q trong do 3 diem M,N,P thang hang va diem Q nam ngoai duong thang do. ke caacacc duong thang di qua cac cap diem. co bao nhieu duong thang phan biet? viet ten cac duong thang do
mong cac ban giai ho minh!
1. Tren 1 duong thang xy lay 4 diem phan biet A,B,C,D hay chi ra cac tia doi nhau
2. cho 10 diem trong do khong co ba diem thang hang . Cu qua hai diem ta ve duoc 1 duong thang . Hoi co tat ca bao nhieu duong thang?
3. cho n diem trong do khong co ba diem nao thang hang . Cu qua hai diem trong so cac diem do ve duoc 1 duong thang. Biet rang co 435 duong thang tao thanh .Tim n?
Tren duong thang xy lay 1 diem O va hai diem M,N sao cho Om = 2 cm; ON = 3 cm. Ve cac diem A va B tren duong thang xy sao cho M la trung diem cua OA; N la trung diem cua OB. Tinh do dai AB ( cach lam nua va dung noi ten ban ra)
lay muoi mot diem M,N,P,Q,A,D,F,G,R,T,S trong do khong co ba diem nao thang hang . Ke cac duong thang di qua cac cap diem . Co bao nhieu duong thang ( phan biet ) ? Viet ten cac duong thang do .
cho n diem A1,A2,A3,....An( n>hoac =2) trong do ko co 3diem thang hang nao. cu 2 diem ke mot duong thang .
a) Ke ten cac duong thang neu n=4
b) tinh so duong thang tren hinh ve neu n=42
c) Tinh n biet so duong thang la 630
cho hai duong thang a va b song song. tren duong thang a lay 10 diem phan biet, tren duong thang b lay 15 diem phan biet. hoi co the ve bao nhieu duong thang phan biet qua 2 trong cac diem da cho ?
cho duong thang xy,tren do lay ba diem O ,P, Q.Hoi co bao nhieu doan thang? Ke tencac doan thang do?
- Ve va ke ten cac doan thang co hai dau mut trong so cac diem M,N,P,Q
- Ve cac duong thang,moi duong di qua hai trong so cac diem M,N,P,Q. Khi do ke ten cac duong thang phan biet
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