cho hinh thang can day nho CD=4cm, goc A + goc B=1/2(goc C + goc D) ,AC vuong goc voi BC.Tinh chu vi hinh thang can ABCD
Cho hinh thang ABCD, AB//CD co AB=4cm, CD=9cm, goc ADB=goc BCD
a) chung minh tam giac ABD dong dang voi tam giac BDC
b) BD=...?
cho hinh thanh ABCD AB//CD co gocA -gocD =200,goc B= 2 goc C.
tinh cac goc cua hinh thang
Cho hinh thang ABCD co AB // CD. Goc C < goc D. CMR AC > BD.
Cho hinh thang ABCD(AB//CD) va AB<CD, co BC=15cm, duong cao BH=12cm, DH=16cm.
a) Tinh HC
b) Chung minh DB vuong goc voi BC
c) Tinh dien tich hinh thang ABCD
ai giup minh cau c) voi minh cam on nhieu
Cho hinh binh hanh ABCD co goc A=120* duong phan giac cua goc D di qua tung diem M cua canh AB.?
a, chung minh AB=2AD
b, ve AH vuong goc voi CD. Chung minh DM=2AH
c, DA vuong goc voi AC
hinh thang ABCD (AB//CD) co goc ACD = goc BDC. Chung minh rang ABCD la hinh thang can
cho hinh thang ABCD ( AD song song BC ) . Co goc ADC = 600 , AC vuong goc CD , AC la tia phan giac goc BAD
Tinh goc DAC , goc DAB
Tinh cac goc cua hinh thang
cho hinh thang abcd (ab//cd) co bc = bd . goi h la trung diem cua cd. duong thang qua h va cat ac va ad lan luot tai e va f . cm goc dbf bang goc ebc