I got an answer from the teacher. As it turns out, they were supposed to draw a 4cm line segment and then eyeball it to draw two more 4cm segments from those points. Which is what we started out with, but it was tricky to get them to come out in the right spots. She said they are just introducing them to the concepts.

Because, you know, math and geometry aren't precise things. Just guess at it.

Hmph. I think we'll name it Tony when it's finished.