Reuleaux triangle

Etymology
Named after Franz Reuleaux, 19th-century German engineer, who used Reuleaux triangles in his machine designs.

Noun

 * 1)  A figure consisting of three circular arcs, each centered on the intersection of the other two.

Translations

 * Finnish: Reuleaux'n kolmio
 * French:
 * Russian: треуго́льник Рёло́