1) Can you find a tangent vector? Think about the slope.

Can you then find a perpindicular direction? (m -> -1/m).

2) You know the dot-product, probably in two forms.

One algebraically and one more geometrical, with cos(a) in there.

Use both to set-up a formula for the angle between two vectors.

3) If you've seen it, use a known formula for the point-plane distance.

If not, find the equation of the line through the point perpindicular to the plane.

This will intersect the plane, you don't have to find a point-point distance.