Geo Unit 1 vocab


a location that has no shape or size and is named by a capital letter (point A, or A)


made up of points and has no thickness or width. there is exactly one line that goes through any two points. (can be written with a cursive letter or two points with a line over them)


a surface that is made up of points that extends infinitely in all directions. There is exactly one plane through any three points not on the same line. (written like Plane ABC or with cursive letter)


points that lie on the same line


points do not lie on the same line


points that lie on the same plane


points do not lie in the same plane


a statement that is accepted as true without proof


a statement or conjecture that can be proven true by undefined terms, definitions, and axioms.

undefined terms

not fully explained by means of more basic words.


assigns properties to a mathematical object

defined term

can be explained using undefined terms and/or other defined terms

line segment

the measurable part of a lines that consists of two endpoints and all of th epoints between them.


when a point on a lines segment is collinear and between two endpoints;


when two geometric figures have exactly the same shape and size.

congruent segments

segments that have the same or equal measure