Geometry Mod 3A (Deductive Reasoning)

conditional

statement that can be written in "if then" form

converse

q then p; switch hypothesis and conclusion

hypothesis

p; phrase following the "if" in a conditional statement

inverse

~p then ~q; negate both the hypothesis and conclusion

logically equivalent

statements with the same truth value

theorem

statement that can be proven

conclusion

q; phrase following "then" in a conditional statement

contrapositive

~q then ~p; switch and negate the hypothesis and conclusion

conjecture

educated guess based on known information

deductive

reasoning based facts, definitions, postulates, theorems, etc

counterexample

an example that proves a conjecture is false

postulate

statement accepted without proof

inductive

reasoning based on past observations

reflexive

AB=AB or Angle ABC= Angle ABC

Symmetric

if AB=CD, then CD=AB

Transitive

if Angle ABC=Angle DEF, then Angle DEF=Angle XYZ, then Angle ABC=Angle XYZ

Through any two points there is _line

exactly one

through any 3 noncollinear points there is plane

exactly one

A line contains two points

at least

A plane contains at least 3 __points

noncollinear

If two points are in a plane, then the line that contains them is ___in the plane

in

If two intersect then their intersection is a point

lines

If two ____intersect, then their intersection is a line

planes

If M is the midpoint of AB then_

AM=MB

If B is between A and C, then_

AB + BC = AC

If R is on the interior of Ang ABC, then_= Ang ABC

Ang ABR + Ang BRC

If two angles form a linear pair, then they are _

supplementary

If the noncommon sides of two adjacent angles form a right angle, then the two angles are_

complementary

Angles supplementary to the same angle are__

congruent

Angles complementary to the same angle are ___

congruent

Vertical angles are

congruent

lines intersect to form four right angles

perpendicular

All _angles are congruent

right

Perpendicular lines form congruent _angles

adjacent

If two angles are congruent and then each angle is a right angle

supplementary

If two congruent angles form a linear pair, then they are angles

right