On graph paper, graph lines $\overleftrightarrow{AB}$ and $\overleftrightarrow{CD}$ if $\overleftrightarrow{AB}$ can be represented by $y=-\frac{4}{3}x+5$ and $\overleftrightarrow{CD}$ can be represented by $y=\frac{3}{4}x-1$. Label their intersection $E$.  

1. What is the relationship between the lines? How do you know?

   Hint (a):

   Examine each line's slope to determine the relationship between the two lines.

2. If $E$ is a midpoint of $\overline{CD}$, what type of quadrilateral could $ADBC$ be? Is there more than one possible type? Explain how you know.

   Hint (b):

   The diagonals are perpendicular. At least one of the diagonals is bisected.