Hi if i was needing to find the angle between the plane

P:r = (0,0,1) + lambda(1,1,0) + mu(0,1,2)

and the line

L: z=0, y=4x+1

I think the equation of the line would be (1, 5 0)

and i believe that the plane is bounded by the direction vectors (1,1,0) and (0,1,2)

I was told be a friend to try and use the trig identity of cos(pi/2 -x) = sin x

any help or just a push in the right direction for this would be greatly appreciated