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

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).