truyen cung mot nua mat phangco bo la duong thang chua tia Ox
Ve cac tia Om,On,Oa,sao cho :goc xOa =60 , goc xOm = 120 ,goc xOn = 40
Ve tia Oy la tia phan giac cu goc mOn
a . goc mOn = ? , goc mOa =? , goc nOa =?
b . goc yOm =? , goc yOn =? , goc yOa =?
c . Ve tia doi cua tia Ox la tia Ox' ;So sanh goc x'Om va goc xOy , goc x'Oa va goc xOm
d . Tia Oa co la tia phan giac cua goc xOm khong ,vi sao