How do you draw imaginary lines?

Answer by  Hewitt302 (1720)

Buy an invisible ink pen. Usually for around a few dollars, maybe less. You can get the pen with refillable ink at any toy store, look in the magic cards and magic kits section. Make sure to get a pen that will make the ink disappear, then reappear after a few seconds. Loads of fun.

Answer by  skwiglez (641)

In your mind I guess. I am not sure what she is talking about. I would draw a line and label it imaginary.