the study of the properties of and relationships between plane curves, figures, etc
plane geometry in American English
the branch of geometry dealing with plane figures
plane geometry in American English
noun
Math
the geometry of figures whose parts all lie in one plane
Word origin
[1740–50]This word is first recorded in the period 1740–50. Other words that entered Englishat around the same time include: automatic, baseline, damper, masthead, professional