Points that lie on the
same line
Collinear points
points that don't lie on
the same line
Non-collinear points
objects which lie on the
same plane
Coplanar objects
objects which don't lie
on the same plane
Non-coplanar objects
statement that we
accept without proof
Postulate
statement that we can
prove using logic
Theorem
the intersection of two
lines
Point
the intersection of two
planes
Line
two coplanar lines that
don't intersect
Parallel lines
two points and all
points between them
Segment
segments with equal
lengths
Congruent segments
point that divides a
segment into two
congruent segments
Midpoint
object that divides a
segment into two
congruent segments
Segment bisector
a part of a line that has
only one endpoint
Ray
rays with the same
endpoint which
together form a line
Opposite rays
two rays joined by a
common endpoint
Angle
common endpoint of
two rays that form an
angle
Vertex
angle with measure less
than 90 degrees
Acute angle
angle with measure
exactly 90 degrees
Right angle
angle with measure
between 90 degrees
and 180 degrees
Obtuse angle
angle with measure
exactly 180 degrees
Straight angle
object (such as a ray or
line) which divides an
angle into two congruent
angles
Angle bisector
a unit to measure angles
which equals a fraction
(1/360th) of a circle
Degree
the number of degrees
in one-fourth of a
circle
90
the number of degrees
in one-half of a circle
180
the number of degrees
in a circle
360
angles whose measures
are equal
Congruent angles
coplanar angles with a
common vertex and side,
but no common interior
points
Adjacent angles
a pair of angles whose
measures add to 90
degrees
Complementary angles
a pair of angles whose
measures add to 180
degrees
Supplementary angles
a pair of supplementary
and adjacent angles
Linear pair
a pair of “opposite”
angles formed by a pair
of intersecting lines
Vertical angles
a statement that can
be written in the form,
"if p, then q.“
Conditional statement
the given information:
part of a conditional
statement found
immediately after the
word if
Hypothesis
the result of the
hypothesis: part of a
conditional statement
found immediately after
the word then
Conclusion
example showing a
statement is not
ALWAYS true, and is
therefore false
Counterexample
statement obtained from
a conditional statement
by switching the
hypothesis and the
conclusion
Converse
statement obtained from
a conditional statement
by negating the
hypothesis and the
conclusion
Inverse
statement obtained from
a conditional statement
by negating AND
switching the hypothesis
and conclusion
Contrapositive
statement combining a
conditional statement
with its converse using
the phrase "if and only if“
Biconditional statement
MYP and PSC only
a diagram with two or
more overlapping circles,
used to show
relationships between
sets.
Venn Diagram
If p --> q is a true
conditional and p is
true, then q is true.
Law of Detachment
If p --> q and q --> r are
true conditionals, then
p --> r is true.
Law of Syllogism
lines that have a point
in common
Intersecting lines
coplanar lines that do
not intersect.
Parallel lines
lines that intersect at
right angles
Perpendicular lines
lines that are noncoplanar and do not
intersect
Skew lines
lines that intersect but
are not perpendicular
Oblique lines
The steepness of a line
expressed as a ratio,
using any two points on
the line
Slope
a line that intersects
two other lines, at
different points
Transversal
a pair of angles, both in
the same position relative
to two lines crossed by a
transversal (that is, upper
right, etc)
Corresponding angles
One pair of
corresponding angles is
2 and  ___
4
a pair of angles, both
between two parallel lines
and on opposite sides of
the transversal
Alternate interior
angles
One pair of alternate
interior angles is
2 and  ___
6
a pair of angles, both
exterior to two parallel
lines and on opposite
sides of the transversal
Alternate exterior
angles
One pair of alternate
exterior angles is
1 and  ___
5
a pair of angles, both
between two parallel lines
and on the same side of
the transversal
Consecutive interior lines
One pair of consecutive
interior angles is
2 and  ___
3
a pair of angles, both
exterior to two parallel
lines and on the same side
of the transversal
Consecutive exterior
angles
One pair of consecutive
exterior angles is
8 and  ___
5