Fr.: angle d'aberration
The angle tilt required by the → stellar aberration phenomenon in order that a moving telescope points directly to a star.
The figure formed by two lines extending from a common point; the figure formed by two intersecting planes (dihedral angle).
L. angulum (nominative angulus) "corner," a dim. form from PIE *ang-/*ank- "to bend". Cf. Skt. ankah "hook, bent," Gk. angkon "elbow," angkura "anchor," Lith. anka "loop," O.E. ancleo "ankle," O.H.G. ango "hook," Av. ank- "curved, crooked," Av. angušta- "toe," Mod.Pers. angošt, angol, angul "finger".
Zâviyé from Ar. zâwiyat "corner, angle".
angle of deviation
Fr.: angle de déviation
The angle between the → incident ray of light entering an → optical system (such as a prism) and the → refracted ray that emerges from the system. Because of the different indices of refraction for the different wavelengths of visible light, the angle of deviation varies with wavelength.
angle of emergence
Fr.: angle d'émergence
The angle of the light coming out of a medium. For a medium with parallel sides (such as a glass slab) it is equal to the angle of incidence.
angle of incidence
Fr.: angle d'incidence
The angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence. Also called → incidence angle.
angle of inclination
Fr.: angle d'inclinaison
1) General: The angle between one plane and another, or
the angle formed by a reference axis and a given line.
angle of minimum deviation
zâviye-ye kažraft kaminé
Fr.: angle de déviation minimale
The angle between the light entering and exiting the prism when the light passing through the prism is parallel to the prism's base. Angle of minimum deviation (D) is used to measure the → index of refraction (n) of the prism glass, because: n = sin [(A + D)/2]/sin (A/2), where A is the → prism angle.
angle of prism
Fr.: angle de prisme
→ prism angle.
angle of reflection
zâviye-ye bâztâb (#)
Fr.: angle de réflexion
The angle between the reflected ray and the normal to the reflecting surface.
angle of refraction
zâviye-yé šekast (#)
Fr.: angle de réfraction
The angle between the direction in which a ray is refracted and the normal to the refracting surface.
Fr.: angle azimutal
In → spherical coordinates, an angle measured from the x-axis in the xy-plane.
Azimuthal, adj. from azimuth; → angle.
Fr.: angle de blaze
The angle between the operating facet of the grooves and the overall plane of a diffraction grating.
→ blaze; → angle.
Fr.: angle de Bragg
The grazing angle between an incident beam of X-rays and a given set of crystal planes for which the secondary X-rays from the planes combine to give a single beam.
zâviye-ye Brewster (#)
Fr.: angle de Brewster
Fr.: angle complémentaire
Any angle that when added to another one creates a 90° angle.
Fr.: angle composé
An angle that results from the combination of two other angles. These angles are expressed by → compound angle formulae.
compound angle formula
disul-e zaviye-ye candsâxt
Fr.: formule d'angle composé
One of eight equations that give the → trigonometric functions
of → compound angles.
Fr.: angles congrus
Two angles if they have the same measure. Congruent angles may lie in different orientations or positions.
Fr.: triangles congrus
Two triangles when all corresponding sides and interior angles have the same measure. The triangles will have the same shape and size, but one may be a mirror image of the other.
Fr.: angles conjugués
Two angles whose sum is 360° or 2π radians.