What is the area of parallelogram abcd in square units

My way of solving this if to make four triangles and one rectangle out of this shape.

Use AB, BC, CD, DA to make the triangles.
The left-overs make up a rectangle that has the area of 2x3, which is 6.

Triangle AB and CD are equivalent, they are both (1/2)(1)(3)=1.5 each, which add up to 3.

Triangle AD and BC are equivalent, they are both (1/2)(1)(4)=2 each, which add up to 4.

So, just add up the 6 from the rectangle and the 3 & 4 and you get 13.

The area of that parallelogram is 13.