We don't have synonyms for plane angles yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are plane angle and phase angles.
(n) :
(geometry) An angle formed by two intersecting straight lines.
(n) :
(geometry) An angle formed by two intersecting planes, measured by the angle between two intersecting straight lines that are in respective planes and perpendicular to the intersection of the planes.
(n) :
(geometry) An angle formed by two intersecting straight lines.
(n) :
(geometry) An angle formed by two intersecting planes, measured by the angle between two intersecting straight lines that are in respective planes and perpendicular to the intersection of the planes.