tren cung 1 nua mat phang co bo chua tia Ox, ve tia Ot va Oy saocho goc xOt = 30 do, goc xOy= 60 do
a, hoi tia nao nam giua 2 tia con lai? vi sao?
b, tinh goc tOy
c, tia Ot co la tia phan giac cua goc xOy hay khong? giai thich.
giup minh voi minh can gap