The area of the quadrilateral is 30 u².
To find the area, you can simply count all of the individual squares in the rectangle, or you can use the area formula, which is length·width = Area. To use this, you could find the length and the width, and multiply them. The length is 6 and the height is 5 so, you would multiply 6 · 5 = 30.
Hope this helps. Good luck! :)