Xét hình thang `ABCD` có : `AB////CD`
\(\widehat{A}=2\widehat{D}\)
`=>`\(\widehat{D}=3\widehat{A}\)
\(\widehat{A}+\widehat{D}=180^0\)
`=>` \(\widehat{D}=180^0:3=60^0\)
\(\widehat{A}=60.2=120^0\)
Còn dữ kiện ko bạn nhỉ ?
cho hinh thang can abcd co duong cheo bd vuong goc voi canh ben bc, bd la tia phan giac cua goc d.tinh chu vi cua hinh thang , biet bc=a
BAI 1 : cho hinh thang ABCD khong co goc vuong biet tong do dai 2 canh day AB va CD thi bang do dai canh ben AD cmr cac duong phan gaic trong goc A vs goc D di qua trung diem E cua BC
Bai 2 : cho hinh thang ABCD co AB//CD cmr neu CD = AD + BC thi cac duong phan giac cua cac goc A va B cat nhau tai 1 diem thuoc canh day CD
Lam giup mink vs mink dang gap lam . THANKS
Hinh thang ABCD: AB song song CD co goc A tru goc B bang 20 do, goc B bang 2gocC.tinh cac goc cua hinh thang
cho hinh thang ABCD AB//CD co goc D =60 do,AB=AD
a,Tinh cac goc cua hinh thang
b,chung minh BD la tia phan giac cua goc ADC va tinh goc DBC
ve hinh luon nhe
cho hinh thanh ABCD AB//CD co gocA -gocD =200,goc B= 2 goc C.
tinh cac goc cua hinh thang
Cho hinh thang vuong ABCD co goc A=B= 90do duong cheo BD vuong goc voi canh ben BC va BD=BC
a,Tinh cac goc cua hinh thang
b,Biet AB=3cm .Tinh do dai cac canhBC.CD
cho hinh thang ABCD day AB, CD cac duong phan giac cac goc ngoai tai dinh A, D cat nhau o M . Cac duong phan giac goc ngoai tai dinh B, C cat nhau o N
a/ chung minh MN//CD
b/ tinh chu vi hinh thang ABCD biet MN=4cm
Cho hinh thang can ABCD (AB//CD) co DB la tia phan giac cua goc D ;DB vuong goc BC biet AB =4cm .Tinh chu vi hinh thang
hinh thang ABCD (AB//CD) ta co ^B-^C=24,^A-1,5^D tinh cac goc cua hinh thang
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
