NL Theory Question

[ThePopinjay]

Here's a situation that comes up often where I am often befuddled. I have top pair on a low board, say 835 and K8 is my hand. I 3/4 pot it 3 handed out of position. Button calls, headsup. The button is very loose, and slightly aggressive. He probably has something like 24. Turn is a Q. How much should I bet or should I check and why?