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/conclusion 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 and 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 ___ 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 Angle ABC, then __ = mAngle ABC.

mAngle ABR + mAngle RBC

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