Hello mahnoosh, sorry to hear about the damage with the Tablet. Well Of course if you have the option and the unit is in warranty you may want to call your local Acer to do a repair at cost to keep in warranty. If you are looking at doing a self repair you may need to search online for the LCD/glass. Just Google it and I’m sure there are a few places.
“No one messes around with a nerd’s computer and escapes unscathed.” ― E.A. Bucchianeri