Adds a rectangle to a path
#include <GDIPlus.au3>
_GDIPlus_PathAddRectangle ( $hPath, $nX, $nY, $nWidth, $nHeight )
| $hPath | Pointer to a GraphicsPath object | 
| $nX | X coordinate of the upper-left corner of the rectangle | 
| $nY | Y coordinate of the upper-left corner of the rectangle | 
| $nWidth | Width of the rectangle | 
| $nHeight | Height of the rectangle | 
| Success: | True. | 
| Failure: | False and sets the @error flag to non-zero, @extended may contain GPSTATUS error code ($GDIP_ERR* see GPIPlusConstants.au3). | 
Search GdipAddPathRectangle in MSDN Library.
#include <GDIPlus.au3>
#include <GUIConstantsEx.au3>
Example()
Func Example()
    Local $hGUI, $hGraphic, $hBrush, $hPath1, $hPath2, $hMatrix
    ; Create GUI
    $hGUI = GUICreate("GDI+", 800, 200)
    GUISetState(@SW_SHOW)
    _GDIPlus_Startup()
    $hGraphic = _GDIPlus_GraphicsCreateFromHWND($hGUI) ;Create a graphics object from a window handle
    _GDIPlus_GraphicsSetSmoothingMode($hGraphic, $GDIP_SMOOTHINGMODE_HIGHQUALITY) ;Sets the graphics object rendering quality (antialiasing)
    _GDIPlus_GraphicsClear($hGraphic, 0xFFFFFFFF)
    $hBrush = _GDIPlus_BrushCreateSolid(0xFFFF0000)
    $hPath1 = _GDIPlus_PathCreate() ;Create new path object
    For $i = 1 To 9
        _GDIPlus_PathAddRectangle($hPath1, 20 * $i, 10, 10, 180)
    Next
    $hPath2 = _GDIPlus_PathCreate() ;Create new path object
    For $i = 1 To 9
        _GDIPlus_PathAddRectangle($hPath2, 10, 20 * $i, 180, 10)
    Next
    _GDIPlus_GraphicsFillPath($hGraphic, $hPath1, $hBrush) ;Draw path1 to graphics handle (GUI)
    _GDIPlus_PathAddPath($hPath1, $hPath2) ;add path2 to path1
    $hMatrix = _GDIPlus_MatrixCreate()
    _GDIPlus_MatrixTranslate($hMatrix, 300, 0)
    _GDIPlus_PathTransform($hPath2, $hMatrix) ;move path2 to an offset of 300
    _GDIPlus_GraphicsFillPath($hGraphic, $hPath2, $hBrush) ;Draw path2 to graphics handle (GUI)
    _GDIPlus_MatrixTranslate($hMatrix, 300, 0)
    _GDIPlus_PathTransform($hPath1, $hMatrix) ;move path1+Path2 to an offset of 600
    _GDIPlus_GraphicsFillPath($hGraphic, $hPath1, $hBrush) ;Draw path1 to graphics handle (GUI)
    _GDIPlus_GraphicsDrawString($hGraphic, "+", 180, 10, "Arial Black", 100)
    _GDIPlus_GraphicsDrawString($hGraphic, "=", 480, 10, "Arial Black", 100)
    ; Loop until the user exits.
    Do
    Until GUIGetMsg() = $GUI_EVENT_CLOSE
    ; Clean up resources
    _GDIPlus_MatrixDispose($hMatrix)
    _GDIPlus_PathDispose($hPath1)
    _GDIPlus_PathDispose($hPath2)
    _GDIPlus_BrushDispose($hBrush)
    _GDIPlus_GraphicsDispose($hGraphic)
    _GDIPlus_Shutdown()
EndFunc   ;==>Example