le huyen linh
17/08/2018 at 08:54-
jimin bts cute 17/08/2018 at 09:01Two corners \(xOy\) and \(yOy'\) compensated \(\widehat{xOy}+\widehat{yOy'}=180^o\).
Imagine: \(\widehat{yOy'}=180^o-\widehat{xOy}=180^o-120^o=60^o\).
So \(\widehat{yOy'}=60^o\)
le huyen linh selected this answer.