I'm sorry about the issue, the only solution you can do is to restore the ipad, which will cause you to lose all data (photos, files, ect...) currently on it. If you made a backup prior to losing the password, you should be able to restore that.
Here are the steps to restore the ipad :
1-Download Itunes from : https://www.apple.com/itunes/download/
2-Install itunes and plug in your iPad to your pc
3-press and hold the home button and the sleep/wake/power button at the same time for 45 seconds until the Apple logo appears, once that appears you can release the buttons
4-iTunes will give message iTunes has detected an iPad in recivery mode you must restore this iPad to continue
5-click restore if it does not go through click on the iPad in the left hand side of iTunes and click restore
6-restore iPad and now you should have your iPad back.
Additional Information : https://www.youtube.com/watch?v=Shrc3FeCJEQ
Hope this help, if you need further help please let me know and i will gladly continue to help