GRE question - unintersection I'm struggling to visualize the following GRE problem:

The solution says that for $m$ and $n$ to intersect on the right, it has to be the case that $2x+3x>180$, after that we get $x>36$. But I don't understand why. I can see that if $m$ and $n$ are parallel then $2x+3x = 180$ though. Can someone help me visualize this problem? Thanks. 

This is the classic example of Euclid's fifth postulate, the parallel postulate.
Here, we talk about the angles on the opposite side to which the lines intersect with each other. Hence, their sum must be greater than $180^\circ$.
