Geometry Terms

34 terms

If B is between A and C, then AB+BC=AC
sum of the parts equals the whole

linear pair postulate

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

right angles congruence theorem

all right angles are congruent

congruent supplements theorem

if two angles are supplementary to the same angle (or to congruent angles) then they are congruent

congruent complements theorem

if two angles are complementary to the same angle (or to congruent angles) then the two angles are congruent

vertical angles congruence theorem

Vertical angles are congruent

deductive reasoning

reasoning in which a conclusion is reached by stating a general principle and then applying that principle to a specific case (The sun rises every morning; therefore, the sun will rise on Tuesday morning.)

inductive reasoning

reasoning from detailed facts to general principles

law of detachment

if the hypothesis of a true conditional statement is true, then the conclusion is also true

law of syllogism

If "p-q" and "q-r" are true statements, then "p-r" is a true statement.

conditional statement

a type of logical statement that has two parts, a hypothesis and a conclusion

complementary angle

two angles that add up to 90 degrees

supplementary angle

When the sum of the measures of a pair of angles add up to 180°

2 angles that have the same vertex and a common ray but no interior points in common

linear pair

two adjacent angles whose non-common sides are opposite rays supplementary angle

conjecture

a statement that is believed to be true without proof

counter example

an example that shows a conjecture is false

if point B lies in the interior of <AOC then m<AOB+m<BOC=m<AOC

bi conditional statement

a statement that contains the phrase "if and only if"

a=a

If a=b, then b=a

transitive property

If a=b and b=c, then a=c

converse

the statement formed by switching the hypothesis and conclusion of a conditional statement

inverse

the statement formed when you negate the hypothesis and conclusion of a conditional statement

contra-positive

switches and negates the parts of an "if...then" statement

2 angles that have the same vertex and a common ray but no interior points in common

substitution property

If a=b, then a can be substituted for b in any equation or expression

If a=b, then b=a

vertical angles

a pair of opposite congruent angles formed by intersecting lines

congruent angles

Angles that have equal measures

division property

if a=b, then a/c = b/c