Question

@ganeshie8
While solving for the shortest distance between two skew lines I came across a method
Distance=BA.Unit vector of PQ
Where BA is the vector obtained by subtracting starting point of a line with the other and Unit vector of PQ is the normal passing through both lines. How is the method correct?

If
r1 = a1+tb1, r2=a2+sb2
BA = a1-a2
PQ = b1 x b2/|b1 x b2| { x means cross product }

Answer 1

@Irishboy123

Answer 2

First consider a "point" and a "line" in 2D :

Answer 3

Yes I know how to calculate in 2D.
Dot product / magnitude of b = a cos theta

Answer 4

Would you agree that the shortest distane between that point to the line is the perpendicular ?

Answer 5

Of course