đặt $a=\widehat{A};b=\widehat{B}$$\widehat{C}+\widehat{D}=360-(a+b)$$\Rightarrow \widehat{OCD}+\widehat{ODC}$ $=180-\frac{(a+b)}{2}$$\Rightarrow \widehat{COD}=180-$ đỏ $=180-180+\frac{a+b}{2}=\frac{a+b}{2}$Đúng click "V" chấp nhận đúng dùm Jin
đặt $a=\widehat{A};b=\widehat{B}$$\widehat{C}+\widehat{D}=360-(a+b)$$\Rightarrow \widehat{OCD}+\widehat{ODC}$ $=180-\frac{(a+b)}{2}$$\Rightarrow \widehat{COD}=180-$ đỏ $=180-180+\frac{a+b}{2}=\frac{a+b}{2}$
đặt $a=\widehat{A};b=\widehat{B}$$\widehat{C}+\widehat{D}=360-(a+b)$$\Rightarrow \widehat{OCD}+\widehat{ODC}$ $=180-\frac{(a+b)}{2}$$\Rightarrow \widehat{COD}=180-$ đỏ $=180-180+\frac{a+b}{2}=\frac{a+b}{2}$
Đúng click "V" chấp nhận đúng dùm Jin