A love triangle.
A set square.
The structure of systems composed with three interrelated objects.
A triangular piece of equipment used for gathering the balls into the formation required by the game being played.
A draughtsman's square in the form of a right-angled triangle.
A polygon with three sides and three angles.
A triangular formation of railway tracks, with a curve on at least one side.
A frame formed of three poles stuck in the ground and united at the top, to which people were bound when undergoing corporal punishment.
Any of various large papilionid butterflies of the genus Graphium.
A percussion instrument made by forming a metal rod into a triangular shape which is open at one angle. It is suspended from a string and hit with a metal bar to make a resonant sound.
The practice of three people having sex, i.e. having threesomes.
The practice of two people having sex while a third person watches (and may or may not take part).