cho M la diem khong ba diem nao thang hang cu qua 2 diem cu ve mot doan thang co 10 doan thang vay M =
Cho 9 diem trong do khong co 3 diem nao thang hang . Cu di qua 2 diem la duoc mot doan thang.
Hoi co the ve duoc bao nhieu doan thang ?
minh khong biet viet dau nen cac ban thong cam !
Cho 10 diem trong do khong co 3 diem nao thang hang. Cu qua 2 diem ta lai ve 1 doan thang. Hoi co bao nhieu doan thang?
có 45 đoạn thẳng hàng
vì n.(n - 1 ) : 2 = 10.(10-1) :2 =45 đoạn
đúng hông ta ??
cho doan thang mn=10. Tren tia MN ve diem P sao cho doan thang MP co do dai bang 5cm
a.Trong ba diem M,N,P diem nao nam gua 2 diem con lai
b.So sanh do dai doan thang MP va PN
c.Diem P co la trung diem cua doan thang MN khong ? Vi sao ?
M________________P________________N
a/vì M;N;P thẳng hàng mà MP<MN(5cm<10cm)
=>P nằm giữa M và N
b/ vì P nằm giữa N ;M
=>MP+PN=MN
=>5+PN=10
=>PN=5cm
=>PM=PN=5cm
c/ vì P nằm giữa M và N
mà PM=PN=5cm
nên P là tia phân giác của MN
Cho 10 diem trong do co 4 diem thang hang , ngoai ra khong co 3 diem nao thang hang nua qua 2 diem ta veduoc 1 doan thang,1 duong thang . Hoi co bao nhieu doan thang, duong thang
Cau 5: Trong cac khang dinh sau, khang dinh nao dung, khang dinh nao sai?
1.Ba diem phan biet la ba diem thang hang.
2.Voi ba diem phan biet luon co hai diem nam ve cung phia doi voi diem con lai.
3.Voi ba diem thang hang phan biet luon co hai diem nam khac phia voi diem con lai.
4.Voi ba diem A,B,C thang hang thi diem B luon nam giua hai diem A,C.
5.Co mot va chi mot duong thang di qua hai diem (phan biet) cho truoc.
6.Hai duong thang phan biet thi song song voi nhau.
7.Hai tia chung goc thi cung nam tren mot duong thang.
8.Hai tia chung goc thi doi nhau
9.Neu diem M nam giua diem A,B thi no la trung diem cua doan thang AB.
10.Neu MA=MB thi M la trung diem cua doan thang AB.
11.Neu MA+MB= AB va MA=MB thi M la trung diem cua doan thang AB.
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cho 2016 diem trong do khong co ba diem nao thang hang va cu qua hai diem ta ve duoc mot duong thang hoi co tat ca bao nhieu duong thang
Số đường thẳng là:
\(\frac{2016.\left(2016-1\right)}{2}=2031120\)(đường thằng
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?
bai1 cho n diem trong do khong co 3 diem nao thang hang .Cu qua 2 diem ta ve mot duong thang biet rang co tat ca 105 duong thang .Tinh n
1 điểm cắt 104 điểm còn lại tạo nên 104 giao điểm.Vậy có 104x105 giao điểm.Vì mỗi đường thẳng được tính 2 lần là\(\frac{104.105}{2}=5460\)giao điểm
TA CO : N.(N-1)/2 =105
=> N.(N-1)=210
=> N.(N-1)=14.15
=> N=15
K NHE
cho 2013 diem phan biet . trong do 13 diem thang hang . cu qua 2 diem ta ve 1 doan thang . hoi tat ca co bao nhieu doan thang