Villain is quite agressive preflop 47\33\6%(BTN) and passive postflop 13% flop raise, 35% bet vs missed cbet, 26% fold to cbet.

Grabbed by Holdem Manager
NL Holdem $1(BB) Replayer
SB ($117)
BB ($120)
UTG ($39.25)
UTG+1 ($13.70)
Hero ($100)
BTN ($113)

Dealt to Hero K A

fold, fold, Hero raises to $3, BTN calls $3, fold, fold

FLOP ($7.50) 9 7 2

Hero ???

If I start betting, then I probably should go for 3 streets to get value from his draws or fold a pair. I dont like this line w\o at least some backdoors.
If we check, he will probably freeroll his draws and will try to get to SD cheap w weak pairs. And we probably cant call his bets. I cant decide which line is better here.

c/f?

you can c/f since he doesnt like to give up and you dont have that many reads on him. with backdoor fd id bet

Id probably at least double barrel and maybe call blank river.

can you explain this?

check fold/ try to get to showdown

check fold

Well, villain is a passive fish postflop as op said who will call with any overcards/draws on the flop so its a v bet. Turn is also a v bet and if he calls and bets river and draws miss, its an easy hero call.

seems like a standard c/f