Geomentry Unit 1 Flashcards
Induction
A way of thinking that uses observations and experiences to form rules
Conjecture
A statement that appears to be correct based on observations, but is not proved true. Can not use in proofs unless proven. Conclusions could be false.
Conditional statement
if A then B statement, A is assumed and B is the conclusion. Must assume is true.
Deduction
A way of thinking that starts with rules, and then figure out what must be true based on what is given. Conclusions are always true.
Venn Diagram
In a venn diagram the if part of the sentence is in the small circle and the big part is for the then part of the statement.
negate
make negetive
converse
- flip
-if B then A
Inverse
- make negetive
- If not A, then not B
Contrapositive
-Make negetive and flip
- If not B, then not A
symbol for Contrapositive and inverse
L upside down and backwards. hook
Biconditional statement
If a conditional statemant and its converse is true then its a biconditional statement. if and only if statement
Syllogiism
if A then B
If B then C
so If A then C
postulate / axiom
a statemet that is assumed to be true without proof . Like a rule. Accepted as true.
common notion
A thing that is not officially defined but understood by common sense
Undefined term
Basic terms in geomentry : point, line, plane
other types of proofs
proof by contradictionor indirect proof - assumeing the opposite of what is given . If A then not B
flowchart proof
theoems
A statement that has already been proven to be true. Can be used in proofs.
Corollay
A statement that naturally follows or makes sense based on something already proved. Depends on theorems. Must be proven
What can be used in proofs after proven?
Postulates, Axioms, Theorms, corollaries.
Point
has not length, width, or height
line segement
2 points connected together by lines. Has a length. Does NOT extend on forever
midpoint
the point halfway between the endpoints of a line segement.
Ray
A part of a line that starts at an endpoint and extedns on forvermever. Has length
Line
has a lenght extends on foever
what has infinate lenght?
ray and line
angle bisector
a ray that divded an anle into 2 angles
supplemntayr
180
complementary
90
0 dimensonal
has no lenght, width, or height, a point
1 d
has lenght
segments, rays, lines
collinear
when 2 or more points lie on the same line
Unque line assumtion
through any 2 points there is exactly one line
2d
has lenght and width
triangle, recatngle , square, etc
plane/ coplanar
infinte 2d surface. Coplanr meas to be on the same plane
geometric pspace
ifnate 3d, all objects there
vertical angles
a pair of opposite angles formed by interseciting lines. has equal measure.
perpendicualr bisector
a line that cuts a line segemtn at a right angle
skew lines
lines that re not on the smae plane. do not intersect and is not parrell
