So I got this two vectors and I have used the pytagoream theorem to. But I'm still kinda sketchy about the answer I get.
46225+7225 = 53450
sqrt 53450 = 231km
Did I do it right?
You only can use the Pythagorean theorem if the vectors are perpendicular to each other.
In your case the vectors include an angle of 135° and therefore you have to use the Cosine rule:
$\displaystyle d = \sqrt{85^2+215^2-2 \cdot 85 \cdot 215 \cdot \cos(135^\circ)}$
I've got $\displaystyle d \approx 281.59\ km$