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.
Cho goc xOy va goc yOz ke bu nhau, ve tia Om la tia phan giac cua goc xOy va tia On la tia phan giac cua goc yOz
a) Tinh goc mOn.
b) Ve tia Om' la tia doi cua tia Om, neu goc zOm' = 30 do. Tinh goc m'Oy.
c) Ve duong thang d khong di qua diem O, tren duong thang d lay 2015 diem phan biet. Tinh so goc co dinh la diem O va cac canh di qua 2015 diem tren duong thang d.
Cho goc xOy va goc yOz ke bu nhau, ve tia Om la tia phan giac cua goc xOy va tia On la tia phan giac cua goc yOz
a) Tinh goc mOn.
b) Ve tia Om' la tia doi cua tia Om, neu goc zOm' = 30 do. Tinh goc m'Oy.
c) Ve duong thang d khong di qua diem O, tren duong thang d lay 2015 diem phan biet. Tinh so goc co dinh la diem O va cac canh di qua 2015 diem tren duong thang d.
cho tam giac ABC vuong o A. 2 canh le voi goc vuong la :AC=15cm, AB=16cm. diem E nam tren canh AC co AE =1/2 AC. tu diem E , ke duong thang song song voi AB cat canh BC tai F . tinh do dai doan thang .
cho tam giac abc co goc a vuong , ab= 30cm , ac=45cm.M la 1 diem tren canh ab sao cho am=20cm. Tu M ke duong thang song song voi canh bc cat canh ac tai diem n.Hoi: a/ tinh S abc, b/ tinh S anm
tren duong thang xy lay them 2012 diem M1, M2,M3,..,M2012 phan biet voi nhau va phan biet voi cac diem A, B,O,I co the ve duoc bao nhieu goc dinh C ma cac canh la cac tia goc C va di qua cac diem da cho tren duong thang xy
cho hình chữ nhật abcd m va n la 2 diem tren canh AB Sao cho mn = 1/3 Ab . P va q la 2 diem tren canh CD sao cho pq = 1/2 Cd hai duong thang mn va pq cat nhau tai o va Dien tich opq lon hon dien tich omn 1.5 cm2tim dien tich hinh chu nhat abcd
trong cac khang dinh sau khang dinh nao dung A)2 tia chung goc la 2 tia doi nhau B)2 duong thang phan biet thi k co diem chung C)neu M la trung diem cua doan thang AB thi MA=MB D)co it nhat 1 duong thang di qua 2 diem A va B
1 thua vuon hinh tam giac ABC vuong o A . canh AC lon hon canh AB 30m. canh BC dai 150m
a, tinh do dai canh AB va AC. biet chu vi thua vuon do la 360m
b, tinh dien tich thua vuo do.
nhung ai di hoc he thi kb voi mk nhe