If we say dilation, we mean to say that the endpoints or the corners of the polygon is move by the number of scale factors away from the original point. Unfortunately, you missed to give here an illustration of both quadrilaterals, it would have been easy for us to answer this item should we have been given with the dimensions.
No. The area of a square/rectangle is length * height, and 4 * 20 is 80m^2. Because Yoshi has a can of paint that can cover 81m^2, and 81m^2 > 80m^2, Yoshi does NOT need to buy more paint.
