geometry: chapter 2 Flashcards
converse
Interchanging the conclusion and the hypothesis of a conditional
conditional
basic form of if p then q p is the hypothesis and q is the conclusion
counter example
An example that shows that the hypothesis is true and the conclusion is false in an if then statement
theorem 2-1 midpoint theorem
if M is midpoint of line AB then AM = 1/2 AB and MB= 1/2 AB
theorem 2-2 angle bisector theorem
if ray BX is the bisector of angle ABC then the measure of angle ABX= 1/2 the measure of angle ABC etc
reasons used in proofs
given information
definitions
postulates
theorems that have been proven
complementary angles
two angles whose measure has the sum of 90
supplementary angles
two angles who measure have the sum of 180
theorem 2-3
vertical angles are congruent
theorem 2-4
If two lines are perpendicular then they form congruent adjacent angles
perpendicular lines
Two lines that intersect to form right angles
theorem 2-5
If two lines form congruent addition angles then the lines are perpendicular
theorem 2-6
If the exterior sides of two adjacent acute angles are perpendicular then the angles are complementary
theorem 2-7
If two angles are supplements of congruent angles than the two angles are congruent
theorem 2-8
If two angles are complements of conquering angles then the two angles are congruent