Respuesta :
Answer:
40 cm
Step-by-step explanation:
Each point of the final 6-pointed star has 2/3 of the perimeter of the equilateral triangle. So, the 6 points have a total perimeter of ...
6(2/3)(10 cm) = 40 cm
The perimeter of the final star is 40 cm.

Answer:
40
Step-by-step explanation:
The star has $12$ sides. Each side is one-third of the perimeter of a triangular tile, or $\frac{10}3$ cm. So the perimeter of the star is
$12\cdot\frac {10}3 = 4\cdot 10 = \boxed{40\text{ cm}}.$
Alternatively, consider that the original tiles are composed of $12$ triangles with $3$ sides each, which have $12\cdot 3 = 36$ sides in all. Only $12$ of those $36$ sides make up the perimeter of the star. $12$ is one-third of $36,$ so the perimeter of the star is one-third of the total perimeter of the tiles. The tiles have a total perimeter of $10 \cdot 12=120\text{ cm},$ so the perimeter of the star is $\frac{120}3 = 40$ cm.