We have the following:
In this case we have that the angles of A and C are equal and that B and D are also equal.
We have that the sum of all the angles is equal to 360 °
[tex]\begin{gathered} A=C=38,B=D \\ A+B+C+D=360 \\ \text{replacing} \\ 38+B+38+B=360 \\ 2B=360-38-38 \\ B=\frac{284}{2} \\ B=142\text{\degree} \\ D=142\text{\degree} \end{gathered}[/tex]
