Are they similar? How or how not?

No, Triangle VNU is not similar to triangle MNL because the corresponding angles are not equal.
Similar triangles are triangles with equal corresponding angles and equal side ratios . This means that the ratio of the corresponding sides are equal.
angle VNU = angle MNL ( vertical angles)
angle VNU = 52°
angle V = 180 -( 52 + 68)
angle V = 180 - 120
angle V = 60°
angle L = 180 - ( 52 + 72)
angle L = 180 - 124
angle L = 56°
since angle L is not equal to angle V then the triangles are not similar.