Glossary

 Shirley, Kenny. //SparkNote on Building Blocks of Geometry//. 6 Sep. 2008 .
 * Building blocks of Geometry**

Colinear - Lying in one line (usually refers to a set of points).

Congruent - Of exactly the same size and shape; in other words, of exactly the same dimensions.

Coplanar - Existing in one plane (usually refers to points or lines).

Dimension - The number of lines required to span a region in space.

Line - A collection of points arrayed in a straight formation without limit.

Noncolinear - Not lying in one line (usually refers to a set of points).

Noncoplanar - Not existing in one plane (usually refers to points or lines).

Perpendicular - At a 90 degree angle (something is perpendicular relative to something else).

Plane - A flat, boundless surface in space.

Point - A specific location in space.

Ray - A portion of a line with a fixed endpoint on one end that extends without bound in the other direction.

Segment - A portion of a line with two endpoints and, thus, finite length.

Space - The collection of all points.


 * Inductive and Deductive Reasoning ** 

**Axiom** - A statement about real numbers that is accepted as true without proof.

 * Deductive Reasoning** - A form of reasoning by which each conclusion follows from the previous one; an argument is built by conclusions that progress towards a final statement.


 * Inductive Reasoning** - A form of reasoning in which a conclusion is reached based on a pattern present in numerous observations.


 * Postulate** - A statement about geometry that is accepted as true without proof.


 * Theorem** - A statement in geometry that has been proved.


 * Undefined Terms** - Terms that aren't defined, but instead explained; they form the foundation for all definitions in geometry.


 * Logic Statements ** 

**Conclusion** - The clause of a conditional statement that begins with "then."

 * Conditional Statement** - A statement with "if-then" structure; it has an "if" clause and a "then" clause.


 * Conjunction** - Two statements joined by the word "and" into a single statement; //p//âȧ//q//.


 * Contrapositive** - A conditional statement whose hypothesis and conclusion were negated and switched. Given //p//âȧ//q//, the contrapositive is âȼ//q//âȧâȼ//p//.


 * Converse** - A statement whose hypothesis and conclusion were switched. Given //p//âȧ//q//, the converse is //q//âȧ//p//.


 * Declarative Sentence** - A sentence that asserts a fact; a sentence that states something.


 * Disjunction** - Two statements joined by the word "or" into a single statement; //p//âȨ//q//.


 * Hypothesis** - The clause preceded by "if" in a conditional statement; it states the condition.


 * Implication** - Two statements combined into one, in which one statement is preceded by the word "if" and the other statement is preceded by the word "then." Through implication, conditional statements are formed.


 * Inverse** - A statement whose hypothesis and conclusion were both negated. Given //p//âȧ//q//, the inverse is âȼ//p//âȧâȼ//q//.


 * Negation** - The opposite of a statement; its truth value is the opposite of the original statement.


 * Statement** - A declarative sentence that is definitely either true or false.


 * Truth Table** - A table, or chart, that displays the truth values for the statements in it for every possible scenario.


 * Truth Value** - The truth or falsehood of a statement. Every statement has exactly one of two truth values: either true or false (T or F).