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Sorry for such a newbie question. I tried google but can't find anything similar. I'm using Illustrator CS6 so I don't have CC's rounded corner tool. I tried Effects > Stylize > Round Corners but it doesn't work.
Here's what happens: (as you can see it distorts it)
I also tried applying a stroke to circle and removing the bottom half of circle then applying rounded caps to stroke but I don't like the final result.
This is what i have created by manually adjusting the corners using the pen tool but it looks pretty bad.