Talk:PlanetPhysics/Dihedral Angle

Original TeX Content from PlanetPhysics Archive
%%% This file is part of PlanetPhysics snapshot of 2011-09-01 %%% Primary Title: dihedral angle %%% Primary Category Code: 02.40.Dr %%% Filename: DihedralAngle.tex %%% Version: 1 %%% Owner: pahio %%% Author(s): pahio %%% PlanetPhysics is released under the GNU Free Documentation License. %%% You should have received a file called fdl.txt along with this file. %%% If not, please write to gnu@gnu.org. \documentclass[12pt]{article} \pagestyle{empty} \setlength{\paperwidth}{8.5in} \setlength{\paperheight}{11in}

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Two distinct half-planes, emanating from a same line $l$, divide the space ($\mathbb{R}^3$) into two regions called {\em dihedral angles}.\, The line $l$ is the {\em edge} of the dihedral angle and the bounding half-planes are its {\em sides}.

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The angle, which the sides of a dihedral planes separate from a normal plane of the edge, is the {\em normal \htmladdnormallink{section}{http://planetphysics.us/encyclopedia/IsomorphicObjectsUnderAnIsomorphism.html}} of the dihedral angle.\, Apparently, all normal sections are equal.\, According to the size of the normal section, the dihedral angle may be called acute, right, obtuse, straight, skew, convex and concave.\, Unlike the angle between two planes, a dihedral angle may be over 90 degrees.

If two planes intersect each other and if one of the four dihedral angles formed is right, then also the others are right.\, Then we say that the planes are {\em perpendicular} to each other.

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