The distance between the two parallel lines `vecr = veca_1 + tvecu` and `vecr = veca_2 + svecu` is ...................
`(|vecu xx (veca_1 - veca_1)|)/(|vecu|)`
`(|[(veca_2 - veca_1)vecu vecv]|)/(|vecu xx vecv|)`
`(|veca_2 - veca_1|)/(|vecu xx vecv|)`
None of these