trihedral

American  

[trahy-hee-druhl] / traɪˈhi drəl /

adjective

Geometry.

1. having, or formed by, three planes meeting in a point.

   a trihedral angle.

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noun

1. a trihedron.

trihedral British  

/ traɪˈhiːdrəl /

adjective

1. having or formed by three plane faces meeting at a point

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noun

1. a figure formed by the intersection of three lines in different planes

Other Word Forms

• subtrihedral
  adjective

Etymology

Origin of trihedral

First recorded in 1780–90; tri- + -hedral

Example Sentences

See Examples For:

trihedral

Demonstrate that if two trihedral angles have dihedral angles respectively equal, then their face angles are equal.

From Time Magazine Archive

In solid geometry it is used only in a proposition relating to the volumes of two triangular pyramids having a common trihedral angle, and this is usually omitted.

From The Teaching of Geometry by David Eugene Smith

The connexion indicated between triangles and trihedral angles will also be recognized in Prop.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various

Conceive of the figure as in space, so that M is the vertex of a trihedral angle of which the given triangles are plane sections.

From An Elementary Course in Synthetic Projective Geometry by Derrick Norman Lehmer

The angle between two planes is termed dihedral, between three trihedral, between any number more than three polyhedral.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1 by Various