Explanation:
they are similar, that means for our case here that they're is one central scaling factor for all sides between the 2 triangles.
by looking at the forms of both triangles, we see that
ET corresponds to TR.
FT corresponds to TS.
FE corresponds to RS.
for TE and TR we have the length information :
25 and 40
so, the scaling factor between these 2 corresponding sides can then be used for the other pairs of corresponding sides.
the scaling factor to go from the large to the small triangle is
25/40 = 5/8
therefore,
FT = TS × 5/8 = 22 × 5/8 = 11×5/4 = 55/4 = 13.75
FE = RS × 5/8 = 54 × 5/8 = 27×5/4 = 33.75
the perimeter of TFE is therefore
25 + 13.75 + 33.75 = 72.5