A rigid motion is the action of taking a geometric object in the plane and moving it is some fashion to another position in the plane without changing its shape or size. So if you make six copies of a...A rigid motion is the action of taking a geometric object in the plane and moving it is some fashion to another position in the plane without changing its shape or size. So if you make six copies of a single triangle and put them together at a point so that each angle appears twice, there will be a total of 360° around the point, meaning the triangles fit together perfectly with no gaps and no overlaps.