In the United States, gowns are designed to be worn closed. Your Master's gown will have silly oblong sleeves (bachelors have simple sleeves and doctorates have even sillier ornate sleeves and also have three velvet bands that match the hood trim, and is color-coded for your degree (see below).

Your hood tells your degree and the institution conferring it. Your hood will be 3-1/2 feet long (3' is for a bachelor's and 4' is for a doctorate). The trim of your hood (that's the velvet part that goes around your neck and down your back) will be 3-inches wide (2" is for a bachelor's and 5" is for a doctorate), and should be a dark grayish-brown color (which signifies a degree in commerce, accountancy, or business). The silk lining of your hood (which lays open on your back) will be in the colors of your school and in a specific pattern assigned to just your school (I'd guess some form of green and gold for Argosy University).