Answer:
270°
Step-by-step explanation:
[tex]m\widehat{BC} = 360\degree - (146\degree + 90\degree) \\
m\widehat{BC} = 360\degree -236\degree \\
m\widehat{BC} = 124\degree \\\\
m\widehat{ABC} =m\widehat {AB} + m\widehat {BC} \\
m\widehat{ABC} =146\degree + 124\degree \\
\huge \red {\boxed {m\widehat{ABC} =270\degree}} \\
[/tex]
