Chung minh rang 1 hinh vuong co the chia thanh mot so bat ki lon hon 5 hinh vuong nhung khong thê chia thanh dung 5 hinh vuong
Cho 2 hinh chu nhat co cung dien tich .HInh 1 co kich thuoc a va b (a lon hon b) hinh 2 co kich thuoc c va d (c lon hon d) .chung minh rang nêu a lon hon c thi chu vi cua hinh1 lon hon chu vi hinh 2
cho hinh thoi ABCD ,goi O la giao diem cua hai dong cheo ACva BD .qua B ve duong thang song song voi AC,qua C ve duong thang song song voi BD ,chung cat nhau tai I
a)chung minh OBICla hinh chu nhat?
b)chung minh AB=OI
c)tim dieu kien cua hinh thoiABCDde tu giac OBIC la hinh vuong
Cho hinh vuong ABCD. Goi E la mot diem tren canh BC. Qua B ke tia Bx vuong goc voi AE, Ax cat CD tai F. Trung tuyen AI cua tam giac AEF cat CD tai K. Duong thang qua E song song voi AB va cat AI tai G. CM:
a) AE = AF va tu giac EGFK la hinh thoi
b) AF2 = FK.FC
c) Khi E thay doi tren BC thi chu vi tam giac EKC van khong doi
mot hinh vuong co chu vi bang chu vi hinh chu nhat cochieufgscnvncvbsrẻtkvcxvfvyqwhs4jehjdhhujyryywdhfbchcz53d
mot hinh thang can co 2 duong cheo vuong goc voi nhau .day nho dai 13,724 cm.canh ben dai 21,867 cm.tinh day lon hinh thang do
Hinh thang ABCD co day Lon CD=10cm day nho bang duong cao duong cheo vuong goc voi canh ben tinh duong cao hinh thang
cho (O;R) duong kinh AB, M nam tren (O;R) voi M A<MB. tiep tuyen tai M cat tiep tuyen tai A,B theo thu tu C,D. AD cat (o) tai E; OD cat MB tai N. duong thang vuong goc voi AB tai O cat AM tai F. chung minh tu giac OFDB la hinh chu nhat
cho tam gia OAN vuong tai O , OA = 3cm và ON = 4cm .Phan giac cua AON cat AN tai E .
a)Tinh AE va NE .
b) tu E ke EH va EK lan luot vuong voi OA ,ON . Tu giac OHEk la hinh gi tinh chu vi va dien tich cua OHEk