M1m2 = m1g+GM+MH+m2h = 2 (GM+MH) = 2gh = BC (triangle median theorem),

And ∵m 1 m2∑n 1 N2, ∴ quadrilateral m1n2m2 is a parallelogram.

Its circumference is 2n1N2+2m1n1= 2bc+2mn.

∵BC=6 is a constant value, and the perimeter of∴ quadrilateral depends on the size of MN.

As shown in Figure 2, it is a complete schematic diagram before cutting and splicing.

The quadrilateral PBCQ is a rectangle, which is half of the rectangle ABCD.

∫M is any point on the PQ line, and n is any point on the BC line.

According to the shortest vertical line segment, the minimum value of MN is the distance between PQ and BC parallel lines, that is, the minimum value of MN is 4;

And the maximum value of MN is equal to the length of the diagonal of the rectangle, that is = =

∫ Quadrilateral perimeter M 1N 1N2M2 = root 2BC+ root 2MN= 12+2 times root MN,

∴ The minimum perimeter of quadrilateral M 1N 1N2M2 is 12+2×4=20.

The maximum value is 12+2×= 12+4 times the root sign 13.

So the answer is: 20, 12+4 times the root sign 13. ..