Sheet Metal Bench Radius

Hi

I have a sheet-metal radius bench to make up from separate sheetmetal radius parts.

Have a look at the attached part A.

The edge flange will be a separate part laser cut out from sheet-metal then welded round the radius at the angle on my drawing.

How do i make this a separate component so i can laser cut this out or how do i work out the correct radius to make a seperate part ?

Thanks

SolidworksSheet Metal