| In other words, the trisection of any angle, by the use of the straightedge and compasses alone, is impossible. |
| A rule for the cubic equation by which the problem of trisection is solved has been given by Cardan. |
| There is one trisection which is of more importance than that of the angle. |
| But while we cannot trisect the angle, we may easily approximate trisection. |
| Because of confusion with national flags, the design was changed in July 1946 to trisection horizontally with, from top to bottom, dark blue, yellow and red. |
| His problems of the trisection of the angle, and the duplication of the cube, are curious and interesting. |
