On circles which cut out from three lines segments of given length (Q1339057)

Apart from the circumcircle, a triangle ABC has three circles that cut out from the lines BC, CA, AB segments whose lengths are equal to those of the sides of the triangle. \textit{L. Stammer} [ibid. 47, No. 4, 158-168 (1992; Zbl 0777.51007)] showed that the centres of these three circles are the vertices of an equilateral triangle, a result reminiscent of Morley's theorem. In the present paper the author gives a short elementary proof of this result.