plane section vs surface area

plane section and surface area both are nouns.

Word	Noun	Adjective	Verb	Adverb
plane section	Yes	No	No	No
surface area	Yes	No	No	No

As nouns, surface area is a hypernym of plane section; that is, surface area is a word with a broader meaning than plane section:

plane section: (geometry) the area created by a plane cutting through a solid
surface area: the extent of a 2-dimensional surface enclosed within a boundary

Other hypernyms of plane section include area, expanse.

plane section (noun)	surface area (noun)
(geometry) the area created by a plane cutting through a solid	the extent of a 2-dimensional surface enclosed within a boundary