Unit 2: Reasoning and Proof Test Review

Two-column proof

a format for a proof that has numbered statements and corresponding reasons that show an argument in a logical order

Paragraph proof

a format for a proof that presents the statements and reasons of a proof as sentences in a paragraph

Flowchart proof

a format for a proof that uses boxes and arrows to show the flow of a logical argument

Line Perpendicular to a Plane

a line intersects a plane on a point and is perpendicular to every line in the plane that intersects at that point

Proof

a logical argument that uses deductive reasoning to show that a statement is true.

Conditional Statement

a logical statement that has two parts, a hypothesis and a conclusion. If p, then q.

Inductive Reasoning

a process that involves looking for patterns and making conjectures

Deductive Reasoning

a process that uses facts, definitions, accepted properties and the laws of logic to form logical arguments

Counterexample

a specific case for which the conjecture is false

Theorem

a statement in geometry that must be proven true

Converse

a statement that exchanges the hypothesis and the conclusion of a conditional statement. If q, then p.

Contrapositive

a statement that negates both hypothesis and the conclusion of the CONVERSE of a conditional statement

Inverse

a statement that negates both the hypothesis and the conclusion of a conditional statement. If not p, then not q.

Conjecture

an unproven statement that is based on observations

Hypothesis

p, follows the if

Conclusion

q, follows the then

Negation

the opposite of the original statement

Perpendicular Lines

two lines that intersect to form a right angle

Biconditional Statement

written when a conditional statement and its converse are BOTH true. p if and only if q.