Answer:
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
