$\\\text{* Vì $\widehat{AOD}$ và $\widehat{AOC}$ là hai góc kề bù}$ $\\\text{nên $\widehat{AOD}+\widehat{AOC}=180^0$}$ $\\\to\text{$\widehat{AOD}=180^0-\widehat{AOC}$}$ $\\\text{$\widehat{AOD}=180^0-130^0=50^0$}$ $\\\text{*Vì $\widehat{BOC}$ và $\widehat{AOC}$ là hai góc kề bù}$ $\\\text{nên $\widehat{BOC}+\widehat{AOC}=180^0$}$ $\\\to\text{$\widehat{BOC}=180^0-\widehat{AOC}$}$ $\\\text{$\widehat{BOC}=180^0-130^0=50^0$}$ $\\\text{* Vì $\widehat{BOC}$ và $\widehat{BOD}$ là hai góc kề bù}$ $\\\text{nên $\widehat{BOC}+\widehat{BOD}=180^0$}$ $\\\to\text{$\widehat{BOD}=180^0-\widehat{BOC}$}$ $\\\text{$\widehat{BOD}=180^0-50^0=130^0$}$
