Hi Felix, so notice in Burr's video above how he just uses the line drawing tool and that's all that is needed for putting in tan/tan lines - he just places the line in nearby where the tan/tan line is, then there will be a snap point created on the second circle (or curve, it works on any bendy curve as well) right at the tan/tan location and if you put your mouse on it the tan/tan snap will engage which will also move the base point of the line. You can tell when that special tan/tan snap engages because a "Tan/Tan" tag will appear on not only the end point of the line but also the start point of the line as well - with that snap the start point of the line is also adjusted. Here's a previous video of this in action:



Move your mouse a little ways along the second curve until you find the tan/tan point and then you'll have these lines you need without doing any special extra construction work.

- Michael