Group the given figures into three classes using each figure only once.

1, 5, 8 are all open figures bisected by a line segment.

4, 6, 7 are all closed figures touching a line segment.

2, 3, 9 are all closed figures intersected by a line.

3, 5, 8 have similar designs (four leaves placed close to a small circle and forming a symmetrical design at the centre of the figure).

2, 6, 9 have similar designs (three of the corners of the main figure are shaded black and there is a pattern formed around a '+' sign at the centre of the figure).

1, 4, 7 have similar designs (there are four small circles at(the corners of the main figure and there is a wheel shaped element at the centre of the figure).

1, 5, 6 have two similar elements, one inside the other.

2, 3, 4 contain straight lines each dividing, the figure into two equal parts.

7, 8, 9 have one element placed inside a different element.

1, 6, 9 are figures which are half shaded by slanting lines.

2, 4, 7 are all divided into equal parts (either three or four parts) by straight lines and also have a black circle at the centre.

3, 5, 8 have similar designs and have their four corners shaded black.

3, 6, 9 are geometrical figures containing line segments (the number of these line segments is half the number of sides in the figure) parallel to the sides of the figure.

1, 5, 8 consist of a circle and a triangle intersecting it. The triangle is also divided into two equal parts by a straight line.

2, 4, 7 are all funnel shaped figures.