mathematik
posted by abonumilian .
wie bestimme ich den drehpunkt von zwei dreiecken?

or
How do I determine the turning point of 2 triangles? 
I believe the question is to find the centre of rotation of two given congruent triangles, ABC, and A'B'C'. The centre of rotation (drehcentrum) Z is the intersection of the perpendicular bisectors of BB' and that of CC' (both lines not shown in figure).
See figure (for construction of A'B'C':
http://www.blikk.it/angebote/primarmathe/ma2275.htm
(edited: 10:18)