Thanks Gino,
 You have done a lot of work there but unfortunately, you did label  O incorrectly.
  
 \(15^2=m^2+t^2-2mt\cdot cos\alpha\\ Cos\alpha = \frac{2t}{4m}=\frac{t}{2m}\\ so\\ 225=m^2+t^2-2mt \cdot \frac{t}{2m}\\ 225=m^2\\ m=15 \)
  
 This means that  the hypotenuse is  60
 and the sum of the other 2 sides is  112-60 =52
 As guest has already told us very loudly   ,  this is impossible.
,  this is impossible.
  
 So such a triangle cannot exist.
  
 