Resistance is directly proprtional to sq. of length.
Hence after cutting the length becomes l/3, l/3 and l/3 respectively.
Hence Resistances corresponding to those lengths would be:
R = kl^2
and
(let) r = k(l/3)^2
R/r = 9kl^2/kl^2 => 9
r = R/9 => 12/9 = > 4/3 ohm.
Now net
resistance between two points of triangle = >8/3 and 4/3 in parallel.
=> (8/3) * (4/3) /((8/3) + (4/3))
=> (32/9) / 4
=> 8/9 ohm.
