how do i find the angle between a vector and a line?

a=(1,-1,2)

Line (x-1)/2 = (y-4)/5 =(z-6)/8

Answer 1

[Roger Stafford]

   b = [2,5,8]; % vector along line
   ang = atan2(norm(cross(a,b)),dot(a,b)); % Angle in radians between vectors a and b

(Note: If you take a vector b along the opposite direction along the line, the resulting angle will be the supplement of the above - that is, it will be pi minus the above angle. Which answer is correct depends on your definition of the angle between a vector and a line.)