aberration angle zâviye-ye birâheš Fr.: angle d'aberration The angle tilt required by the → stellar aberration phenomenon in order that a moving telescope points directly to a star. → aberration; → angle. |
angle zâviyé, gušé, konj Fr.: angle 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 zâviye-ye kažraft 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 zâviye-ye zomarceš 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 zâviye-ye fotâd 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 zâviye-ye darkil 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; → inclination. |
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 zâviye-ye manšur 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; → reflection. |
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. → angle; → refraction. |
azimuthal angle zâviye-ye sugâni Fr.: angle azimutal In → spherical coordinates, an angle measured from the x-axis in the xy-plane. Azimuthal, adj. from azimuth; → angle. |
blaze angle zâviye-ye beliz Fr.: angle de blaze The angle between the operating facet of the grooves and the overall plane of a diffraction grating. → blaze; → angle. |
Bragg angle zâviye-ye Bragg 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. → Bragg's law; → angle. |
Brewster angle zâviye-ye Brewster (#) Fr.: angle de Brewster The → angle of incidence for which the sum of the incident angle and the → angle of refraction is 90°. The value of Brewster's angle for glass is 57° and for water is 53°. Same as → polarizing angle. → Brewster's law; → angle. |
complementary angle zâviyé-ye osporandé Fr.: angle complémentaire Any angle that when added to another one creates a 90° angle. → complementary; → angle. |
compound angle zâviye-ye hamnât 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 hamnât Fr.: formule d'angle composé One of eight equations that give the → trigonometric functions
of → compound angles. |
congruent angles zâviyehâ-ye damsâz Fr.: angles congrus Two angles if they have the same measure. Congruent angles may lie in different orientations or positions. |
congruent triangles sebarhâ-ye damsâz 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. |
conjugate angles zâviyehâ-ye hamyuq Fr.: angles conjugués Two angles whose sum is 360° or 2π radians. |