A trigonal bipyramid has three equatorial and two axial positions.
Catheter drainage of the bladder relieves trigonal stretch and improves drainage from the upper tract.
A new calculating method has been proposed for the elongation and twist of trigonal prism.
The utility model provides a trigonal pencil which consists of a pencil core and a pencil body, and is characterized in that the trigonal pencil body is arranged on the periphery of the pencil core.
Color ring and a level section of A. H. Munsell color solid were analysed with regular triangle. Schemes for trigonal color design suitable for furniture design were suggested.
