trihedral

[ trahy-hee-druhl ]

adjective

, Geometry.

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

   a trihedral angle.

noun

1. a trihedron.

trihedral

/ traɪˈhiːdrəl /

adjective

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

noun

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

Other Words From

• subtri·hedral adjective

Word History and Origins

Origin of trihedral¹

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

Word History and Origins

Origin of trihedral¹

C18: from tri- + Greek hedra base, seat + -al ¹

Example Sentences

Trihedral, trī-hē′dral, adj. having three equal sides.—n.

From Project Gutenberg

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 Project Gutenberg

We get, for instance, from I. 4, the 687 theorem, If two trihedral angles have the angles of two faces in the one equal to the angles of two faces in the other, and have likewise the angles included by these faces equal, then the angles in the remaining faces are equal, and the angles between the other faces are equal each to each, viz. those which are opposite equal faces.

From Project Gutenberg

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

From Project Gutenberg

If three planes pass through a common point, and if they bound each other, a solid angle of three faces, or a trihedral angle, is formed, and similarly by more planes a solid angle of more faces, or a polyhedral angle.

From Project Gutenberg