cho tam giac ABC . tren BC lay BM =2/3 BC.
a, so sanh dien tich tam giac ABM va AMC; dien tich tam giac AMC va ABC
b, tren AC lay N la trung diem. so sanh dien tich tam giac ANM va dien tich tam giac ABC
cho tam giac abc. tren bc lay diem M sao cho BM= 2 MB. Biet dien tich abc la 9cm vuong. Tinh dien tich tam giac ABM va AMC
cho hinh chu nhat abcd co dien tich 48 cm2 tren canh cd lay diem e sao cho ec 1/2 ed .tren canh bc lay diem m cho bm = 2/5 bc . a/ so sanh dien tich 2 tam giac abm va cem . b/ tinh tam giac aem
cho tam giac abc lay m la diem diem chinh giua bc
a,so sanh dien tich tam giac abm va dien tich tam giac acm
b,so sanh dien tich tam giac abm va dien tich tam giac abc
lam giup minh nhe
a) M điểm giữa của BC nên CM = MB
Tam giác ABM và tam giác ACM có : đáy CM = MB, chung đường cao tương ứng với đáy.
Nên S(ABM) = S(ACM)
b) S(ABC) = S(ABM) + S(ACM) mà S(ABM) = S(ACM)
Nên \(S\left(ABM\right)=\frac{1}{2}S\left(ABC\right)\)
1/2 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000% luob
1/2 dung 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000% luon minh the
cho tam giac abc .tren canh bc lay d sao cho bd =2 lan dc.noi ad ,lay e bat ki ad . so sanh dien tich tam giac bae va tam giac cae
CHO TAM GIAC ABC . TREN AB LAY DIEM M SAO CHO AM = 2/3 MB . N TREN AC SAO CHO NA = NC .
A. SO SANH DIEN TICH AMC VA DIEN TICH BMC ?
B. SO SANH DIEN TICH BNC VA DIEN TICH BMC ?
Sr nãy giờ quên mất câu này
A.
Ta có diện tích AMC < diện tích BMC vì AM < BM (gt)
B.
Ta có diện tích BNC < diện tích BMC vì NC < BM
Hình bạn tự vẽ vì cũng dễ mà
CHO TAM GIAC ABC CO DIEN TICH LA 12CM2 . LAY DIEM M TREN CANH BC . BIET DIEN TICH ABM=8CM2 VA BC = 25CM. TINH DAI DOAN BM VA MC
tren canh BC cua hinh tam giac ABC co cac diem M , N sao cho BM = NC . so sanh dien tich cac hinh tam giac ABM ,AMN , ANC.Tinh dien tich moi hinh tam giac do ,biet dien tich hinh tam giac ABC la 77,4 cm vuong
Mà BM=MN=NC(gt)
=> BM=MN=NC=BC/3 (*)
Từ A ta có : \(AH\perp BC\)
Từ đó ,ta thấy : Chiều cao AH của tam giác ABC cũng là chiều cao của tam giác ABM,AMN,ANC chung đáy BC/3 ( từ *)
<=> S ABM=S AMN = S ANC => S ABC: 3
=77,4:3=25,8 cm2
Vậy ...
cho tam giac ABC , diem M nam tren canh BC sao cho BC bang 5 lan BM , diem N tren canh AC sao cho AN banhg 3/4 AC , diem P tren doan MN sao cho NP bang 2/3 NP .so sanh dien tich ABM va dien tich AMP
cho tam giac ABC co dien tich bang 36cm2. tren canh AB lay diem M, tren canh AC lay diem Q va tren canh BC lau diem N sao cho AM=2 BM; BN= 2 CN; CQ = 2 AQ
a) tinh dien tich tam giac ABN
b) tinh dien tich tam giac MNQ