Why can't I airdrop things into my ipad air from my macbook pro retina?

I am trying to transfer some PDF files from my macbook pro retina into my ipad air. My ipad air doesn't get discovered by any of my devices through airdrop, bluetooth, USB, and etc. I contacted Apple Support and the person I was speaking with just told me to use email, dropbox, and other sources. He also mentioned that bluetooth is only used for pairing devices and when I disagreed to that comment, he gave me an attitude. If anyone know how to fix this issue or know anything about this, please feel free to help me resolve this. Thank you!