A plane is headed due west with an air speed of 212 km/hr. It is driven from its course by a wind from due north blowing at 23.6 km/hr. Find the ground speed of the plane and the actual direction of travel.

I'm not sure how to complete this problem correctly. Here is what I have so far:

Vw=-23.6j Vp=-212i

Vtotal=-212i+-23.6j

tan(theta)=23.6/212 --> theta=6.35 degrees

The plane is heading West of South at 6.35 degree. But How do I calculate the ground speed of the plane? Please help!