Answer:
The last pair are vertical.
Step-by-step explanation:

has characteristic equation

which has roots at

. The negative root has multiplicity 2. So the general solution is
3x+4x+5x=90
combine like terms
12x = 90
divide by 12
x = 7.5
sides: 3(7.5) ,4(7.5) ,5(7.5)
22.5, 30, 37.5