Can you even buy a lid without buying the whole toilet?
Call a plumbing supply house they might be able to help Home Despot is useless in these matters
Thanks, Parts. I found one here and took it to my daughter's school:
http://doiturselfplumbing.net/It was a perfect fit.
The tank lid in the picture would not have fit, since the tank lid my daughter broke was actually shaped like a rounded trapezoid.
I got the information off another tank lid and measured and traced it and they had one.
Someone at the school had already gone to Home Despot, and of course they could not sell a tank lid without the tank.