1) Ask them to set you up on a blind date. 2) Tell them it has to be someone they've known for a while.
3) Wait for them to come back to you with: "Oh, (s)he'd be perfect for you!"
4) Allow them to set up a time and date as well give you tips on outfit.
5) Appear at date; never allow double date.
By step 4, you should have a clear picture of how your friend(s) see you. If you don't by then, step 5 should do it. After #5, you have basically 2 choices - to, or not to, stay friends.
If you still don't know after step 5, you have to wake the fuck up!