A statement that can be written in the form "If P then Q," where P and Q are sentences
Conditional statement
If P then Q
Truth table
The visual study of shapes, sizes, patterns, and positions
Undefined terms
Point
Line
Plane
Point
Describes a location, has no size, represented by a dot
Line
Has infinite length, no width or thickness, extends infinitely in two directions, represented by a straight line with two arrowheads
Plane
Flat surface extending infinitely in all directions, has infinite length and width but no thickness, usually represented by a four-sided figure
Defined terms
Collinear points
Non-collinear points
Coplanar points
Non-coplanar points
Linesegment
Ray
Oppositeray
Line segment
Part of a line consisting of two endpoints and all the points in between
Ray
Portion of a line that has only one endpoint and extends infinitely in the other direction
Opposite rays
Rays with a common endpoint but extending in opposite directions
Congruent triangles
Triangles that have the same shape and size, with pairs of corresponding sides and angles being equal
Triangle congruence postulates
Side-side-side (SSS)
Side-angle-side (SAS)
Angle-side-angle (ASA)
Angle-angle-side (AAS)
Parallel lines
Lines that do not intersect or meet each other at any point in a plane, equidistant at all points, and never converging or diverging
Transversallines
Lines that intersect two or more lines at distinct points
Undefined terms
Terms that cannot be precisely defined, can only be described or illustrated
Defined terms
Terms that have a formal definition, used to define even more terms
Axioms/Postulates
Statements accepted as true without proof, can be used as reasons in proving mathematical statements
Theorems
Statements that can be proven, can also be used as reasons in proving other statements
Geometry is the visual study of shapes, sizes, patterns, and positions, occurring in all cultures through at least one of the five strands of human activities: buildings/structures, machines/motion, navigating/star-gazing, arts/patterns, measurement
Parts of a mathematical system
Undefined terms
Defined terms
Axioms/Postulates
Theorems
Point
Describes a location, has no size, represented by a dot
Line
Has infinite length, no width, nor thickness, extends infinitely in two opposite directions, represented by a straight line with two arrowheads
Plane
Flat surface extending infinitely in all directions, has infinite length and width but no thickness, usually represented by a four-sided figure
Defined terms related to points
Collinear points
Non-collinear points
Coplanar points
Non-coplanar points
Subsets of a line
Line segment
Ray
Opposite ray
Line segment
Part of a line consisting of two endpoints and all the points in between
Ray
Portion of a line that has only one endpoint and extends infinitely in the other direction
Opposite rays
Rays with a common endpoint but extending in opposite directions
Axiomatic system
Set of axioms used to derive theorems
Axiom
Statement considered true and does not require proof, basic truth used to prove other statements
For every theorem in math, there exists an axiomatic system that contains all the axioms needed to prove that theorem
Postulates
Distance Postulate
Ruler Postulate
Ruler Placement Postulate
Line Postulate
Plane Postulate
Plane-Point Postulate
Plane-Line Postulate
Plane Intersection Postulate
The Distance Postulate states that for every given pair of distinct points, there corresponds a unique positive real number which is the distance between the points
The Ruler Postulate states that the points of a line can be placed in correspondence with real numbers such that every point corresponds to one real number, every real number corresponds to one point, and the distance between two points equals the absolute value of the difference of the corresponding numbers
The Ruler Placement Postulate states that given any two points on a line, one point corresponds to 0 and the other to a positive real number
The Line Postulate states that given any two distinct points, there is exactly one line containing both points
The Plane Postulate states that any three points that do not lie on the same plane determine a plane
The Plane-Point Postulate states that a plane contains at least three noncollinear points and a space contains at least four noncoplanar points
The Plane-Line Postulate states that if two points lie in a plane, then the line containing them lies on the same plane