how can i draw perpendicular (lines or points) to a particular line. Is there any approach

There are a lot of ways to approach this depending on what exactly you’re trying to do (for example, there’s an infinite number of perpendicular lines to any given line in 3D). I would look up exactly what you need (the Math Stack Exchange seems like a good resource, here’s one possible solution). The Cartesian3 class should have all the basic functions you’ll need (like dot and cross products etc.)