#### Answer

Perpendicular

#### Work Step by Step

We are given two lines written in the form $y=mx+b$, where m is the slope of the line and the point (0,b) is the y-intercept.
$y=f(x)=-3x+6$ and $y=g(x)=\frac{1}{3}x+5$
In order for two lines to be parallel, they must have the same slope. However, $m=-3$ for the first line and $m=\frac{1}{3}$, so they have different slopes and cannot be parallel.
Two lines are perpendicular if the product of their slopes is equal to -1.
$-3\times\frac{1}{3}=-1$
Therefore, these two lines are perpendicular.