Flat pattern from finished part? simple bend

We have a part that we need to control the bend radius and the width of the part after bend.  I would like to take the attached part and flatten it to figure out what our flat pattern should be.  I've only ever done the Sheet Metal tutorial and NOT a sheet metal guy... so I'm looking for one of you to help!  Maybe I'm doing this backwards, I don't know?

Thanks in advance,

Paul

SolidworksSheet Metal