First you need to show the hidden edges.
Right click the view and select Show Hidden Edges.
This shows the hidden entities, but their visibility is not permanent. If you type the escape key now the lines will disappear again.
The next step is to…
Teaches Algebra while you Play!
Play on any device connected to the internet.
New!
Prerequisites: None, anyone can learn.
No Installation Required
Watch from any device connected to the internet.
$19.95
This course makes algebra simple. It's based on skills used in Algebra the Game, and it shows you how to solve real life problems.