Cho

Câu hỏi: Cho $\widehat{xOy}={150}^o$. Vẽ $Ox\text{'}\perp Ox; Oy\text{'}\perp Oy$ sao cho tia Ox',Oy' nằm giữa hai tia Ox, Oy

A. $\widehat{xOy\text{'}}=\widehat{x\text{'}Oy}$ = 30$°$

B. $\widehat{xOy\text{'}}=\widehat{x\text{'}Oy}$ = 45$°$

C. $\widehat{xOy\text{'}}=\widehat{x\text{'}Oy}$ = 40$°$

D. $\widehat{xOy\text{'}}=\widehat{x\text{'}Oy}$ = 60$°$