Ok, let the original triangle area S= 1 (because both sides are taken at the same time, the middle line chart only takes one side)

Now taking 1 midline 1/2 is equivalent to taking1(the first power of 2 = 2) of two triangles and the other is a multiple, that is,1/2 =1-/2.

Now taking two midlines 1/2+ 1/2 2 is equivalent to taking three of four (the square of 4 = 2) and the other is a multiple, that is, 1/2+ 1-65438+.

Now taking three median lines1/2+1/2 2 is equivalent to taking seven of eight (8 = 2 to the third power) and the other one is a multiple, that is,1/2+1/2 3 =

Now 20 12 takes the median line1/2+1/22+12, which is equivalent to taking 2 to the power of 20 12-6065438. 2^2 + 1/2^3+ + 1/2^20 12= 1- 1/2^20 12

So the answer is 1- 1/2 20 12.

Instead of 1, I hope the landlord can understand.

Typing a lot, I hope it will help the landlord.

thank you