I do not know if there is a name for this property, but the question is an interesting one! I think there are two right triangles (6,8,10) and (5,12,13) and two rectangles (3,6,3,6) and (4,4,4,4).
Alan Lipp ----
On Sat, 26 Sep 1998, Richard Beeler wrote:
> How many right triangles, with integreal sides, have their areas = to > their perimeters? How many rectangles with integral sides have this > same property? Is there a gemerally accepted name for any geometric > figure which has this property. (The circle with radius 2 is another) >