Fine the missing length indicated.

144

Step-by-step explanation:

the height is sqrt(65^2-25^2) = 60

the length of the unknow side of the largest triangle is sqrt((25+x)^2-65^2)

or also sqrt(x^2+60^2)

set them to equal

sqrt((25+x)^2-65^2) = sqrt(x^2+60^2)

==> x = 144

The answer would be x=144

i got 86 for this

hope this !

if you need an explanation just ask