inductive reasoning
reasoning based on specific examples or past events
conjecture
unproven statement or rule based on inductive reasoning
counterex
an example that proves the conjecture false
conditional statement
an “if, then” statement that relates a hypothesis to a conclusion; p→q
biconditional statement
converse
order switch; q→p
negation
making one negative “not” ~p
inverse
same order, both negative ~p→ ~q
contrapositive
switch and negative ~q →~p
deductive reasoning
reason using given and previously known facts
rhombus
4 equal sides, diagonals are perpendicular
rectangle
diagonals are congruent
square
4 equal sides, perpendicular and conguent diagonals
square root (x2 -x1)^2+(y2-y1)^2
distance formula
180 (n-2)
interior angle measure formula
x, x, root 2x
side values of a 45 45 right triangle
x, root 3x, 2x
side values of a 30 60 right triangle
n/360 x 2 PI r
arc length formula
n/360 x Pi r ^2
area sector formula
rhombus
diagonals are perpendicular and/or a diagonal bisects 2 angles
rectangle
diagonals are congruent
square
if the diagonals are perpendicular and congruent, and/or a diagonal bisects angles and the diagonals are congruent