2. (Bot.) Oblong or elongated, and having three lateral
angles; as, a triangular seed, leaf, or stem.
{Triangular compasses}, compasses with three legs for taking
off the angular points of a triangle, or any three points
at the same time.
{Triangular crab} (Zo["o]l.), any maioid crab; -- so called
because the carapace is usually triangular.
{Triangular numbers} (Math.), the series of numbers formed by
the successive sums of the terms of an arithmetical
progression, of which the first term and the common
difference are 1. See {Figurate numbers}, under
{Figurate}.
Note: The compasses for drawing circles have adjustable pen
points, pencil points, etc.; those used for measuring
without adjustable points are generally called
dividers. See {Dividers}.
{Bow compasses}. See {Bow-compass}.
{Caliber compasses}, {Caliper compasses}. See {Calipers}.
{Proportional}, {Triangular}, etc., {compasses}. See under
{Proportional}, etc.