My ipad is missing how do I locate it?

If you have marked on iPad, at icloud settings "find my iphone/iPad", at icloud website, using your apple id, you have an option to locate the device.

Regards,

If you turned on Find My iPad in Settings->iCloud on the iPad before it was lost, you can log in to http://icloud.com and attempt to locate it through there.

If you did not turn on find my iPad, then there is no way to locate it.