1.
From Point $B$ to Point $A$ you increase the x coordinate by $2$ and the y coordinate by $1$. Similarly, from point $C$ to point $D$ we use a similar method of increasing x by $2$ and y by $1$. Thus, the coordinates of point D are $(5+2, 1+1) = \boxed{(7, 2)}$
2.
The area of the parallelogram is $8$. Can't explain why because I gotta go.