Perhaps you have other details that you could share.
I totally agree with Dan.
It can be done, but a little bit more info would be appreciated. To create a rectangle you will need coordinates. You can create them randomly but you will still need some range of valid values. See below a sample script that will create a number of rectangles. In this case I took the projected coordinate system with NAD 1983 as datum and defined an extent for values values for xmin and ymin of the rectangles to be created:
def main(): import arcpy import random arcpy.env.overwriteOutput = True # some settings fc_out = r'C:\GeoNet\RandomRectangle\test2.shp' width = 10000 height = 5000 xy_extent = arcpy.Extent(2048900, 549400, 2094700, 573600) number_of_rectangles = 25 # NAD_1983_2011_StatePlane_California_V_FIPS_0405 sr_pcs = arcpy.SpatialReference(103001) feats =  for i in range(number_of_rectangles): # get a random xmin and ymin of the rectangle xmin = random.randrange(xy_extent.XMin, xy_extent.XMax) ymin =random.randrange(xy_extent.YMin, xy_extent.YMax) # create the rectangle pnts = [[xmin, ymin], [xmin, ymin + height], [xmin + width, ymin + height], [xmin + width, ymin], [xmin, ymin]] polygon = arcpy.Polygon(arcpy.Array([arcpy.Point(*pnt) for pnt in pnts]), sr_pcs) feats.append(polygon) # write the rectangle to the output fc arcpy.CopyFeatures_management(feats, fc_out) if __name__ == '__main__': main()
And the result:
Could you elaborate a little more on what you are trying to achieve?