Please expand the basic symbology shapes available to users in ArcGIS Online. Currently, users have the option of a circle, square, or diamond - which all closely align with a few of the basic shapes that are available in the Default category in Desktop. That said, I am currently working on a project that would greatly benefit from expanding the basic symbology set of shapes in AGOL to also include triangles, pentagons, hexagons, and octagons (similar to Desktop).