acute angle(ch 1)
an angle that measures more than 0 degrees, but less than 90 degrees
adjacent angles(ch 1)
two angles that share a common vertex and side, but have no common interior points
angle(ch 1)
A set of points consisting of two different rays that have the same endpoint
angle bisector(ch 1)
a ray that divides an angle into two angles that are congruent
axiom(ch 1)
a rule that is accepted without proof
between(ch 1)
When three points are collinear, one point is between the other two.
collinear points(ch 1)
points that lie on the same line
complementary angles(ch 1)
Two angles whose sum is 90 degrees
congruent angles(ch 1)
two angles that have the same measure
congruent segments(ch 1)
segments that have the same length
construction(ch 1)
A geometric drawing that uses a limited set of tools, usually a compass and straightedge.
coordinate(ch 1)
the real number that corresponds to a point on a line
coplanar points(ch 1)
points that lie on the same plane
defined terms(ch 1)
terms that can be described using known words such as point or line
distance(ch 1)
the absolute value of the difference of the coordinates on a line
endpoints(ch 1)
Points that represent the ends of a line segment or ray
exterior of an angle(ch 1)
the region that contains all the points outside of an angle
interior of an angle(ch 1)
the region that contains all the points between the sides of an angle
intersection(ch 1)
the set of points that two or more geometric figures have in common
line(ch 1)
A line has one dimension. It is represented by a line with two arrowheads, but it extends without end.
line segment(ch 1)
consists of two endpoints and all the points between them
linear pair(ch 1)
two adjacent angles whose noncommon sides are opposite rays
measure of an angle(ch 1)
the absolute value of the difference between the real numbers matched with the two rays that form the angle on a protractor
midpoint(ch 1)
the point that divides a segment into two congruent segments
obtuse angle(ch 1)
An angle that measures more than 90 degrees but less than 180 degrees
opposite rays(ch 1)
If point C lies on AB between A and B, then CA and CB are opposite rays.
plane(ch 1)
A flat surface made up of points that has two dimensions and extends without end, and is represented by a shape that looks like a floor or a wall
point(ch 1)
A location in space that is represented by a dot and has no dimension
postulate(ch 1)
a rule that is accepted as true without proof
ray(ch 1)
AB is a ray if it consists of the endpoint A and all points on AB that lie on the same side of A as B
right angle(ch 1)
an angle that measures 90 degrees
segment(ch 1)
consists of two endpoints and all the points between them
segment bisector(ch 1)
a point, ray, line, line segment, or plane that intersects the segment at its midpoint
sides of an angle(ch 1)
the rays of an angle
straight angle(ch 1)
an angle that measures 180 degrees
supplementary angles(ch 1)
two angles whose measures have a sum of 180 degrees
undefined terms(ch 1)
Words that do not have formal definitions, but there is agreement about what they mean
vertex of an angle(ch 1)
The common endpoint of the two rays that form an angle
vertical angles(ch 1)
two angles whose sides form two pairs of opposite rays
biconditional statement(ch 2)
A statement that contains the phrase "if and only if"
conclusion(ch 2)
The "then" part of a conditional statement written in if-then form
conditional statement(ch 2)
a logical statement that has a hypothesis and a conclusion
conjecture(ch 2)
unproven statement that is based on observations
Contrapositive(ch 2)
the statement formed by negating both the hypothesis and conclusion of the converse of a conditional statement
converse(ch 2)
the statement formed by exchanging the hypothesis and conclusion of a conditional statement
Counterexample(ch 2)
a specific case for which the conjecture is false
deductive reasoning(ch 2)
A process that uses facts, definitions, accepted properties, and the laws of logic to form a logical argument
equivalent statements(ch 2)
Two related conditional statements that are both true or both false
flowchart proof (flow proof)(ch 2)
A type of proof that uses boxes and arrows to show the flow of a logical argument
hypothesis(ch 2)
the "if" part of a conditional statement
if-then form(ch 2)
A conditional statement in the form "if p, then q", where the "if" part contains the hypothesis and the "then" part contains the conclusion
inductive reasoning(ch 2)
A process that includes looking for patterns and making conjectures.
inverse(ch 2)
the statement formed by negating both the hypothesis and conclusion of a conditional statement
line perpendicular to a plane(ch 2)
a line that intersects the plane in a point and is perpendicular to every line in the plane that intersects it
negation(ch 2)
The opposite of a statement
paragraph proof(ch 2)
A style of proof that presents the statements and reasons as sentences in a paragraph, using words to explain the logical flow of an argument
proof(ch 2)
A logical argument that shows a statement is true.
theorem(ch 2)
a statement that can be proven
truth table(ch 2)
A table that shows the truth values for a hypothesis, conclusion, and a conditional statement
truth value(ch 2)
A value that represents whether a statement is true (T) or false (F)
two-column proof(ch 2)
a type of proof that has numbered statements and corresponding reasons that show an argument in a logical order
alternate exterior angles(ch 3)
two angles that are formed by two lines and a transversal and lie outside the two lines and on opposite sides of the transversal
alternate interior angles(ch 3)
two angles that are formed by two lines and a transversal and lie between the two lines and on opposite sides of the transversal
consecutive interior angles(ch 3)
Two angles that are formed by two lines and a transversal that lie between the two lines and on the same side of the transversal
corresponding angles(ch 3)
two angles that are formed by two lines and a transversal that are in corresponding positions
directed line segment(ch 3)
a segment that represents moving from point A to point B is called the directed line segment AB
distance from a point to a line(ch 3)
the length of the perpendicular segment from the point to the line
parallel lines(ch 3)
coplanar lines that do not intersect
parallel planes(ch 3)
planes that do not intersect
perpendicular bisector(ch 3)
A line that is perpendicular to a segment at its midpoint.
skew lines(ch 3)
Lines that do not intersect and are not coplanar
transversal(ch 3)
a line that intersects two or more coplanar lines at different points
angle of rotation(ch 4)
the angle that is formed by rays drawn from the center of rotation to a point and its image
center of dilation(ch 4)
The fixed point in a dilation
center of rotation(ch 4)
the fixed point in a rotation
center of symmetry(ch 4)
the center of rotation in a figure that has rotational symmetry
component form(ch 4)
A form of a vector that combines the horizontal and vertical components
composition of transformations(ch 4)
a combination of two or more transformations to form a single transformation
congruence transformation(ch 4)
a transformation that preserves length and angle measure
congruent figures(ch 4)
geometric figures that have the same size and shape
dilation(ch 4)
A transformation in which a figure is enlarged or reduced with respect to a fixed point
enlargement(ch 4)
a dilation with a scale factor greater than 1
glide reflection(ch 4)
a transformation involving a translation followed by a reflection
horizontal component(ch 4)
The horizontal change from the starting point of a vector to the ending point
image(ch 4)
A figure that results from the transformation of a geometric figure
initial point(ch 4)
the starting point of a vector
line of reflection(ch 4)
A line that acts as a mirror for a reflection
line symmetry(ch 4)
A figure in the plane has line symmetry when the figure can be mapped onto itself by a reflection in a line.
line of symmetry(ch 4)
A line of reflection that maps a figure onto itself.
reduction(ch 4)
a dilation with a scale factor between 0 and 1
reflection(ch 4)
a transformation that uses a line like a mirror to reflect a figure
rigid motion(ch 4)
a transformation that preserves length and angle measure ex. translations, reflections, and rotations
rotation(ch 4)
A transformation in which a figure is turned about a fixed point
rotational symmetry(ch 4)
a figure has rotational symmetry when the figure can be mapped onto itself by a rotation of 180° or less about the center of rotation
scale factor(ch 4)
The ratio of the lengths of the corresponding sides of the image and the preimage of a dilation
similar figures(ch 4)
geometric figures that have the same shape but not necessarily the same size
similarity transformation(ch 4)
a dilation or a composition of rigid motions and dilations
terminal point(ch 4)
the ending point of a vector
transformation(ch 4)
a function that moves or changes a figure in some way to produce a new figure
translation(ch 4)
A transformation that moves every point of a figure the same distance in the same direction