In each row, there are 3 types of shadings of circles - a circle is unshaded, another circle has its right half shaded with vertical lines and yet another circle has its upper half shaded with horizontal lines. There are three specified positions of the two triangles each of which is used only once in a row. Also, two of the figures in each row have one triangle shaded.

In each row, the second figure is obtained by removing the outermost element of the first figure and the third figure is obtained by removing the outermost element of the second figure.

In each row (as well as in each column), the number of rectangles in the second figure is two times the number of rectangles in the first figure and the number of rectangles in the third figure is three times the number of rectangles in the first figure.

There are 3 types of shadings in the triangles, 3 types of legs, 3 positions of circles, each of which is used only once in a single row. The circle is shaded in alternate figures.