A
absolute value The distance of a number from
zero on the number line. (p. 150)
acute angle An angle that measures less
than 90°. (p. 344)
acute triangle A triangle with three acute
angles. (p. 344)
Addition Property of Equality If the same
number is added to both sides of an equation,
the sides remain equal. (p. 132)
additive inverse The opposite of a given
number. (p. 150)
adjacent angles Two angles that are in the
plane and share a common side and a
common vertex, but have no interior points
in common. (p. 334)
algebraic expression A mathematical
expression that contains variables, numbers,
and symbols of operations. (p. 52)
alternate exterior angles A pair of nonadjacent
exterior angles on opposite sides of the
transversal. (p. 336)
alternate interior angles A pair of nonadjacent
interior angles on opposite sides of the
transversal. (p. 337)
angle bisector A ray that divides an angle into
two congruent angles. (p. 333)
arc A part of a circle, with all of its points on
the circle. (p. 352)
area The number of square units needed to
cover a flat surface. (p. 464)
arithmetic sequence A sequence generated
by repeatedly adding or subtracting the same
number. (p. 145)
Associative (grouping) Property Changing the
grouping of the addends (or factors) does not
change the sum (or product). (pp. 222, 254)
axis The horizontal or vertical number line of a
graph or coordinate plane. (p. 308)
B
bar graph A graph that uses bars to show data.
The bars may be of different lengths. (p. 325)
base One of the equal factors in a product; a
selected side or face of a geometric figure.
(pp. 38, 446 )benchmark An object of known measure used
to estimate the measure of other objects.
biased sample A sample in which certain
groups from the population are not
represented. (p. 296)
bisect To divide a line segment or an angle into
two congruent parts. (p. 333)
box-and-whisker plot A graph that includes a
number line showing the extremes (greatest
and least numbers), the median, and the
quartile divisions of a data set. A boxis drawn
on top of the second and third quartiles. The
whiskersare the part of the number line
showing the first and fourth quartiles. (p. 304)
C
capacity The amount, usually of liquid, a
container can hold. (pp. 450, 454)
Celsius (°C) scale The temperature scale in
which 0°C is the freezing point of water and
100°C is the boiling point of water. (p. 166)
central angle An angle whose vertex is the
center of a circle. (p. 352)
certain event The probability of an event that is
certain is 1. (p. 274)
chord A line segment with both endpoints on
a circle. (p. 352)
circle A set of points in a plane, all of which
are the same distance from a point called
thecenter. (p. 352)
circle graph A graph that uses the area of a
circle to show the division of a total amount
of data. (p. 318)
circumference The distance around a circle.
(p. 470)
cluster The grouping of data. (p. 302)
combination A set of items in which order is
notimportant. (p. 278)
commission Money earned equal to a percent
of the selling price of items sold. (p. 432)
Commutative (order) Property Changing the
order of the addends (or factors) does not
change the sum (or product). (pp. 222, 254)
compass An instrument used to draw circles.
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