The Solution.
It is given that
[tex]\begin{gathered} m\angle ABC=70^o \\ m\angle CED=30^o \end{gathered}[/tex]
By alternate angles,
[tex]m\angle BED=m\angle ABC=70^o\text{ (Alternate angles)}[/tex]
But
[tex]m\angle BED=m\angle BEC+m\angle\text{CED}[/tex]
So,
[tex]70=m\angle BEC+30[/tex][tex]m\angle BEC=70-30=40^o[/tex]
Hence, the correct answer is 40 degrees.
