(2) Solution: If there are 9 triangles in the figure, and so on, it is concluded that there are just 1 1 basic triangles on one side of C, then △C includes 12 1 triangles.

So the answer is: 9, 12 1

(3) solution: as shown in the figure, regular triangle AQF and regular hexagon DEFGHQ.

So the answer is: regular hexagon, regular triangle.

(4) Δ a1,Δ a2 is obtained by R transformation as shown in figure Δ a, Δ a3 is obtained by T transformation, and the quadrilateral EFGH. Got it.