The $5.00 coin struck by the Royal Australian Mint is not usually a part of circulating currency and is mainly minted for commemorative reasons and can take form in many shapes, with coins like the Triangular ANZAC series and AC/DC coins saw the $5.00 in a triangular shape.  The $5.00 coin would be one of the largest legal tender coins struck by RAM and is usually only struck for commemorative occasions.