As shown in the figure, the perimeter of the first triangle is known to be 1, its three median lines form the second triangle, and the three median lines of the second triangle form the third triangle, and so on. The perimeter of the first triangle is 1________ .

Let △ ABC be l = a + B + C (a, B, C are trilateral)
(1) The perimeter of the first triangle is a + B + C = 1,
(2) Perimeter of the second triangle = (A / 2) + (B / 2) + (C / 2) = (a + B + C) / 2 = 1 / 2
The median line of a triangle is half the base
(3) The circumference of the nth triangle is 1 / 2 ^ n
(4) The circumference of the 2011 triangle is 1 / 2 & # 178; - # 186; - # 185; - # 185;

As shown in the figure, it is known that the perimeter of △ ABC is 1, its three median lines form the second triangle, and the three median lines of the second triangle form three triangles, and so on, the perimeter of the third triangle is______ ．

According to the theorem of median line of triangle, the perimeter of the second triangle composed of its three median lines is half of the perimeter of the first triangle, that is 12, and so on, the perimeter of the third triangle is (12) 2007

As shown in the figure, it is known that the perimeter of the first triangle ABC is 1, its three median lines form the second triangle EFG, the three median lines of the second triangle form the third triangle hij, and so on, the perimeter of the 2000th triangle is___ ．

According to the theorem of the median line of a triangle, we know that the perimeter of the second triangle composed of its three median lines is half of the perimeter of the first triangle, that is, 12, and so on, the perimeter of the 2000th triangle is (12) 1999

As shown in the figure, the perimeter of the first triangle is known to be 1, its three median lines form the second triangle, and the three median lines of the second triangle form the third triangle, and so on. The perimeter of the first triangle is 1________ .