sigmaAllow = 35000 // psi
width = 9 // inch
p = 150 // Force on shelf - lbs
distance = 6 // inches
FOS = 2

leg1 = 5 // inches
leg2 = 8 // inches
thickness = sqrt(distance * p * FOS * 6 / sigmaAllow / width) // inches
bracket = startSketchOn(XY)
  |> startProfile(at = [0, 0])
  |> line(end = [0, leg1])
  |> line(end = [leg2, 0])
  |> line(end = [0, -thickness])
  |> line(end = [-leg2 + thickness, 0])
  |> line(end = [0, -leg1 + thickness])
  |> close()
  |> extrude(length = width)