\setuppapersize[A4,landscape][A4,landscape]

\setuplayout[

  backspace=1.0cm,

  leftedge=0.5cm,

  leftedgedistance=0.5cm,

  rightedgewidth=0.1cm,

  leftmarginwidth=0.1cm,

  leftmargindistance=0.1cm,

  rightedgedistance=0.1cm,

  rightmarginwidth = 0.1cm,

  rightmargindistance = 0.1cm,

  headerdistance=0.5cm,

  footerdistance=0.5cm,

  topdistance=0.5cm,

  width=fit, 

  height=fit]

\starttext

\showlayout

\stoptext

but the rightmarginwidth = 3.7569cm, not 0.1cm, I do not know why?

what should I do to widen the texwidth?

Thanks!

BEST REGARDS

PengCZ