biet ba diem a,b,c thang hang diem c nam giua hai diem con lai co the chi do do dai cua hai doan thang ma biet dc ba do dai ab,ac,bc ko giai thich cach lam cua ban
cho ba diem a,b,c sao cho b nam giua a,c lam the nao chi do hai lan ma biet duoc do dai cua ca ba doan thang ab,bc,ac, hay neu cach lam khac nhau
Cho 3 diem thang hang A,B,C sao cho B nam giua A va C.Lam the nao de chi do 2 lan,ma biet duoc do dai cua 3 doan thang AB,BC,AC?hay neu cac cach lam khac nhau.
Giúp mk nha mk cần gấp!!!!!
chỉ cần đo 1 lần thôi, đó là đo đoạn AC, sau đó chia cho 2 sẽ ra đoạn AB và = BC
Cho diem C nam giua hai diem A va B, biet AB = 6cm. Goi M va N lan luot la trung diem cua cac doan thang AC va BC.
a) Tinh do dai doan thang MN.
b) Hay neu cach chon diem C de cho do dai doan thang MN gap 3 lan do dai doan MC.
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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ve tuy y 3 diem A , B , C thang hang . Lam the nao de chi do 2 lan ma biet duoc do dai cua cac doan thang AB , BC , CA
cho tia Ox lay hai diem A,B sao cho OA=5cm,OB=2cm a) trong ba diem A,B,O diem nao nam giua 2 diem con lai? vi sao b)tinh do dai doan thang AB c) tren tia doi cua Ox lay diem C sao cho OC=1cm. diem B co la trung diem cua AC ko vi sao
a+Trên tia Ox có OB<OA (2cm < 5cm)
=>Bnằm giữa 2 điểm còn lại
b, Ta có OB+AB=OA
+Thay số OB= 2cm ,OA=5cm
2 +AB=5
AB= 5-2
AB =3(cm)
+Vậy AB = 3cm
c,Trên tia CB có CO<OB(1cm<2cm)
=>Onằm giữa CB
=>CO+OB=CB
+Thay số : CO=1cm, OB= 2cm
1+2=CB
CB= 1+2
CB= 3(cm)
+Vậy CB= 3cm
Vì CB=AB (3cm =3cm)
Bcách đều 2 đầu mút
=>B là trung điểm của AC
Chuyển CB ở phần c dòng đầu tiên thành Cx nhé
tren tia ox lay 2 diem a b sao cho ob=12cm oa=6cm
a. diem A co phai la trung diem cua doan thang OB ko
b. goi I la trung diem cua doan thang AB. tinh do dai doan thang OI
c. M la diem thuoc tia doi cua tia OB. biet khoang cach giua hai diem M va I la 12cm
tren tia ox lay 2 diem a b sao cho ob=12cm oa=6cm
a. diem A co phai la trung diem cua doan thang OB ko
b. goi I la trung diem cua doan thang AB. tinh do dai doan thang OI
c. M la diem thuoc tia doi cua tia OB. biet khoang cach giua hai diem M va I la 12cm
a: Vì OA<OB
nên điểmA nằm giữa O và B
mà OA=1/2OB
nên A là trung điểm của OB
b: BI=AB/2=3cm
=>OI=9cm
cho đoạn thẳng AB dài 6cm . trên tia AB lấy C sao cho AC=2,5cm
a) Trong 3 diem A ,B ,C diem nao nam giua hai diem con lai ? vi sao
b)tinh do dai doan thang BC
c) Diem C co phai la trung diem cua doan thang ab khong ? vi sao