Find the angel between the lines `2x=3y=-za n d6x=-y=-4zdot`

Explanation

The lines are `(x)/(3)=(y)/(2)=(z)/(-6) and (x)/(2)=(y)/(-12) = (z)/(-3)`.
Since `a_(1)a_(2)+b_(1)b_(2)+c_(1)c_(2)=6-24+18=0`, we have
`" "theta=90^(@)`