6. (5 points) For a polygon, define a "growth" operation: as shown in Figure 1, change one of its sides $AB$ to an outward convex polyline $ACDEB$, where $C$ and $E$ are the trisection points of $AB$, and points $C, D, E$ form an equilateral triangle. Therefore, for an equilateral triangle with a side length of 9, after two "growth" operations (as shown in Figure 2), the perimeter of the resulting shape is $\qquad$; after four "growth" operations, the perimeter of the resulting shape is $\qquad$.
【Answer】Solution: The perimeter of an equilateral triangle with a side length of 9 is $9 \times 3=27$
After the first "growth", the perimeter of the resulting shape is: $27 \times \frac{4}{3}=36$
After the second "growth", the perimeter of the resulting shape is: $36 \times \frac{4}{3}=48$
After the third "growth", the perimeter of the resulting shape is: $48 \times \frac{4}{3}=64$
After the fourth "growth", the perimeter of the resulting shape is: $64 \times \frac{4}{3}=\frac{256}{3}=85 \frac{1}{3}$
Answer: After two "growth" operations, the perimeter of the resulting shape is 48, and after four "growth" operations, the perimeter of the resulting shape is $85 \frac{1}{3}$.
Therefore, the answers are: $48,85 \frac{1}{3}$.