We introduce a new geometric tool called n-compass and
show that the famous theorem of Mascheroni and Mohr remains valid if the
traditional compass is replaced by the newly introduced tool.
The main purpose of this note is to investigate
equiangular polygons with rational edges. When the number of edges is the power
of a prime, we determine simple, necessary and sufficient conditions for the
existence of such polygons. As special cases of our investigations, we settle
two conjectures involving arithmetic polygons.