ban dat cau thi chi dc dat 1 mon thoi khong dc dat hai mon khac nhau cung 1 cau hoi.
Toan :
3. , BAI NAY BAN VIET CHO MINH CHU S CAO LEN MOT TI NHE.
Vi tu giac ABCD la hinh chu nhat
⇒ AB = CD = 36cm , AD = BC = 20cm
SABCD = AD.CD = 720 cm2
Vi AM = 1/3 MB
⇒ AM = 1/4 AB = 9cm
Vi BN = NC ⇒ CN = 1/2 BC = 10cm
Ta co :
SAMD = AD.AM = 90 cm2
2
SCND = CD.CN = 180cm2
2
⇒ SMBND = SABCD - SAMD - SCND = 720 - 180 - 90
= 450 cm2
4.
xl khong biet lam
5.
xl khong biet lam
6.
Dien tich taam giac ABC : 50 x 40 :2 = 100 ( cm2 )
Canh DB : 40-10 = 30 ( cm )
2 tam giac vuong ABC,DBE co day AC song song voi DE va chung dinh B
Nen : AB/DB = S ( ABC ) = 40 = 100
S ( DBE ) 30 S ( DBE )
S ( DBE ) la : 30x100 : 40 = 75 ( cm2 )
Tieng viet
2. nhieu qua nen minh bo qua bai nay nha
3. xl khong biet lam
minh chi giup cho bn dc 2 bai thoi a xl nha :((( , thanh that xl
