The triangles are not similar because the smallest sides are 6/10 = 3/5, the medium sides are 8/24 = 1/3, and the longest sides are 10/26 = 5/13 and similar triangles must have the same ratio for all three sides.
10/9 can be rewritten as 1 1/9, so it's closest to 1. 2/15 is really small, so close to 0.
I want to say about 27% but I am not completely sure
I'm pretty sure it's 28 but sorry if I'm wrong it might be 44