Placing your stick at the end of the shadow of the pyramid, you made by the sun's rays two **triangles**, and so proved that the pyramid [height] was to the stick [height] as the shadow of the pyramid to the shadow of the stick.

—

The spider-men came first, and presented her Majesty with a table full of mathematical points, lines and figures of all sorts of squares, circles, **triangles**, and the like; which the Empress, notwithstanding that she had a very ready wit, and quick apprehension, could not understand; but the more she endeavoured to learn, the more was she confounded

—

Poetry is a sort of inspired mathematics, which gives us equations, not for abstract figures, **triangles**, squares, and the like, but for the human emotions. If one has a mind which inclines to magic rather than science, one will prefer to speak of these equations as spells or incantations; it sounds more arcane, mysterious, recondite.

—

Placing your stick at the end of the shadow of the pyramid, you made by the sun's rays two **triangles**, and so proved that the pyramid [height] was to the stick [height] as the shadow of the pyramid to the shadow of the stick.

— W. W. Rouse Ball,

Perhaps the best-known mandala-cum-plotting device in the Tantric universe is the Sri Cakra and Sri Yantra of Hindu Tantric practice, a perfectly balanced three-dimensional geometric diagram of a series of eleven interlocking and embedded **triangles** (also called Cakras) radiating downward and outward from a central point and enclosed by a circle and a square. The mandalas of Buddhist and Jain Tantric practice follow similar structural and dynamic principles.

— By David Gordon White in p. 10-11 (Tantra in Practice)

The Sri Yantra is composed of two sets of **triangles**. One set includes four male **triangles** denoting the four aspects of evolved or limited consciousness. The other set includes five female **triangles** denoting the five vital functions, the five senses of knowledge, the five senses of action, and the five subtle and five physical forms of matter.

— In "Crossing the Healing Zone: From Illness to Wellness", p.160

These two sets of **triangles** are superimposed to show the union of the masculine and feminine aspects of your nature. When united they make the eight lotus petals of the yantra. Four gates or doors called bhupara, surround these **triangles** representing the gates of the consciousness to the deeper mysteries beyond.

— In "Crossing the Healing Zone: From Illness to Wellness", p.160

There is a very good saying that if **triangles** invented a god, they would make him three-sided

— Charles de Montesquieu,