## Need Help to Understand Form Intersections in Lesson 2

##### 4:33 PM, Saturday June 20th 2020

I would like some help understanding how 3D forms intersect. Where I am getting stuck is the concept that "when we draw two forms in space, we decide where exactly they are". In the case of two boxes, the intersection should be a straight line or multiple straight lines. My question is

• Is it correct to say that the first line to draw is completely up to ourselves, as long as it can exist on both planes that intersect? But once that is done, is there is only one correct way to draw rest of the lines? i.e. to make them correctly lying on the surfaces, and as a result, perpendicular to each other in the 3D space?

• Or alternatively, even the first line needs to follow certain constraints?

I drew an example here to clarify my question: https://imgur.com/a/XnMoCTI In the example, there seems to be many ways to draw the intersection but can they all be mathematically correct??