1-1 Points Lines and Planes Flashcards
Geometry
Branch of mathematics that deals with the measurements, properties, and relationships of points, lines, planes, surfaces, and solids.
Undefined terms
Words without formal definitions, but there is agreement about what they mean. Examples include point, line, and plane.
Point (undefined)
a point is a single location in space, has no length or width and is represented by a dot.
line (undefined)
A line has one dimension, is represented by a line with two arrows and is named either by two points on that line, or by a single lower case letter.
collinear
If two or more points lie in the same line, then the points are said to be collinear.
plane (undefined)
A plane has two dimensions, is represented by a 4-sided shape like a parallelogram, but extends without end in all 4 directions.
co-planar
If three or more points lie in the same plane then the points are said to be co-planar.
Conjecture
An unproven statement based on observation.
Postulate
A rule accepted without any proof.
Theorem
A rule or conjecture that can be proved true.
Line Postulate
If two points exists, then there is exactly one line that can go through those two points.
Line segment or segment
A part of a line that has two endpoints
Ray
A part of a line that has one endpoint and goes on forever in the same direction.
Opposite rays
Two rays that share the same endpoint and both go off in opposite directions; together, they create a line.
Intersection
Where two or more geometric figures have the same point or set of points in common.
