Geometry Vocab

1

100

'this' of a statement has the opposite meaning, as well as an opposite truth value

negation

200

a sentence that is neither true nor false

statement

300

counterexample

to show that a conjecture is not true

400

inverse

formed by negating both the hypothesis and conclusion of the conditional

500

algebraic proof

are two or more statements joined together by the word and or or

a proof that is made up of a series of algebraic statements

compound statement

2

100

writing a paragraph to explain why a conjecture for a given statement is true

paragraph proof (informal proof)

200

is a statement or conjecture that has been proven

theorem

300

deductive argument

forming a logical chain of statements linking the given to what you are trying to prove

400

informal proof

writing a paragraph to explain why a conjecture for a given statement is true (paragraph proof)

500

conjunction

follows the word then in a conditional statement

a compound statement using the word and

conclusion

3

100

a statement that is accepted as true without proof

postulate (axiom)

200

a convenient method to organize the truth value of a statement

truth table

300

deductive reasoning

uses facts, rules, definitions, or properties to read a logical conclusion from a given statement

400

inductive reasoning

reasoning that uses a number of specific examples to arrive at a conclusion

500

conjecture

formed by negating both the hypothesis and the conclusion of the converse on the conditional

a concluding statement reached using inductive reasoning

contrapositive

4

100

a logical argument in which each statement one makes is supported by a statement that is accepted as true

proof

200

a statement that is either true or false

truth value

300

disjunction

a compound statement that uses the word or

400

logically equivalent 

when two statements that have the same truth value

5

100

an if-then statement used to relate a particular hypothesis to its conclusion

related conditionals

200

a method used to present a logical argument using a table with two columns

two-column proof

300

hypothesis

follows the word "if" in a conditional statement

400

if-then statement

a compound statement of the form "if p, then q", where p and q are statements

500

conditional statement

formed by exchanging the hypothesis and conclusion of the conditional

a statement that can be written in the if-then form

converse