Farrah Abraham -- 'Wait, Who's Trayvon Martin?'

Farrah Abraham has NO IDEA who Trayvon Martin is -- but she thinks Trayvon is a woman she may have met ... because Farrah Abraham is an idiot.

"Backdoor Teen Mom" made the unbelievably stupid comments on the "Matty P's Radio Happy Hour" show ... when the host asked how she felt about the Trayvon situation.

"I feel like I've met her or something," Farrah blurted out of her stupid mouth ... adding, "It sounds so familiar ... I don't know what she is so I can't picture the person with the name right now."