Two years ago the mathematical world was abuzz about the discovery of a 15th tiling of the plane by convex pentagons (I wrote about it here). Still the question remains: are these the only ones or are ...

THE War Office has published a pamphlet on the modern range-finder, written by Prof. Cheshire, and, as is to be expected from an author of such technical knowledge, it is a clear and thorough ...

Pentagonal prism is the beam Angle (90 °), one of the steering gear.It has two purposes: one is that no matter how much the first incident Angle on the side is the emergent light incident light ...