Sorry to drag these out. Here is the fourth answer to the design test.
The top design illustrates how unity is created by dominance of shape, measure, value, and space interval. These are contrasting shapes, with the triangles dominant. One of the triangles is also dominant in size. There is opposition of value, with the white predominating. The top design is, therefore, unified. The top is more interesting than the bottom design because of the variety produced by the unequal space intervals between the units of the top design.