Given the following parameters
[tex]\begin{gathered} m\angle ABD=104^0 \\ m\angle2=18^0 \\ m\angle1\Rightarrow? \end{gathered}[/tex]
From the diagram, we can say that the <1 and <2 are adjacent.
we can say that.
[tex]m\angle1+m\angle2=104^0[/tex]
Substitute for m<2 =18 degrees in the equation above, to find m<1
[tex]\begin{gathered} m\angle1+18^0=104^0 \\ m\angle1=104^0-18^0 \\ m\angle1=86^0 \end{gathered}[/tex]
Hence, the m<1 is 86°
