Glossary

A    
     
absolute value The distance of a number   from zero; the positive value of a number. at the picture
acute   angle A positive angle measuring   less than 90 degrees.  
acute triangle A triangle each of whose   angles measures less than 90 degrees.  
additive identity The number zero is called   the additive identity because the sum of zero and any number is that number.  
additive inverse The additive inverse of any   number x is the number that gives zero when added to x. The additive inverse   of 5 is -5.  
adjacent angles Two angles that share both a   side and a vertex.  
angle The union of two rays with a   common endpoint, called the vertex.  
arc A portion of the   circumference of a circle.  
area The number of square units   that covers a shape or figure.  
associative property of addition (a + b) + c = a + (b + c)  
associative property of multiplication (a x b) x c = a x (b x c)  
average A number that represents the   characteristics of a data set.  
axis of symmetry A line that passes through a   figure in such a way that the part of the figure on one side of the line is a   mirror reflection of the part on the other side of the line.  
     
B    
     
base The bottom of a plane figure   or three-dimensional figure.  
bisect To divide into two congruent   parts.  
box and whisker plot A type of data plot that   displays the quartiles and range of a data set.  
     
C    
     
Cartesian coordinates A system in which points on   a plane are identified by an ordered pair of numbers, representing the   distances to two or three perpendicular axes.  
central angle An angle that has its vertex   at the center of a circle.  
chord A line segment that connects   two points on a curve.  
circle The set of points in a plane   that are a fixed distance from a given point, called the center.  
circumference The distance around a   circle.  
coefficient A constant that multiplies a   variable.  
collinear Points are collinear if they   lie on the same line.  
combination A selection in which order   is not important.  
common factor A factor of two or more   numbers.  
common multiple A multiple of two or more   numbers.  
commutative property of addition a + b = b + a.  
commutative property of multiplication a*b = b*a.  
complementary angles Two angles whose sum is 90   degrees.  
composite number A natural number that is not   prime.  
cone A three-dimensional figure   with one vertex and a circular base.  
congruent Figures or angles that have   the same size and shape.  
constant A value that does not   change.  
coordinate plane The plane determined by a   horizontal number line, called the x-axis, and a vertical number line, called   the y-axis, intersecting at a point called the origin. Each point in the   coordinate plane can be specified by an ordered pair of numbers.  
coplanar Points that lie within the   same plane.  
counting numbers The natural numbers, or the   numbers used to count.  
counting principle If a first event has n   outcomes and a second event has m outcomes, then the first event followed by   the second event has n times m outcomes.  
cross product A product found by   multiplying the numerator of one fraction by the denominator of another   fraction and the denominator of the first fraction by the numerator of the   second.  
cube A solid figure with six   square faces.  
cylinder   A three-dimensional figure   having two parallel bases that are congruent circles.  
     
D    
     
data Information that is   gathered.  
decimal number The numbers in the base 10   number system, having one or more places to the right of a decimal point.  
degree A unit of measure of an   angle.  
denominator The bottom part of a   fraction.  
dependent events Two events in which the   outcome of the second is influenced by the outcome of the first.  
diagonal The line segment connecting   two nonadjacent vertices in a polygon.  
diameter The line segment joining two   points on a circle and passing through the center of the circle.  
difference The result of subtracting   two numbers.  
digit The ten symbols, 0, 1, 2, 3,   4, 5, 6, 7, 8, and 9. The number 215 has three digits: 2, 1, and 5.  
distributive property a(b + c) = ab + ac  
dividend In a / b = c, a is the   dividend.  
divisor In a / b = c, b is the   divisor.  
     
E    
     
ellipse The set of all points in a   plane such that the sum of the distances to two fixed points is a constant.  
equation A mathematical statement   that says that two expressions have the same value; any number sentence with   an =.  
equilateral triangle A triangle that has three   equal sides.  
equivalent equations Two equations whose   solutions are the same.  
equivalent fractions Fractions that reduce to the   same number.  
error of measurement The difference between an   approximate measurement and the actual measure taken.  
evaluate To substitute number values   into an expression.  
even number A natural number that is   divisible by 2.  
event In probability, a set of   outcomes.  
exponent A number that indicates the   operation of repeated multiplication.  
equivalent fractions Fractions that reduce to the   same number.  
     
F    
     
factor One of two or more   expressions that are multiplied together to get a product.  
factorial To break a number into its   factors.  
face A flat surface of a   three-dimensional figure.  
formula A equation that states a   rule or a fact.  
fraction A number used to name a part   of a group or a whole. The number below the bar is the denominator, and the   number above the bar is the numerator.  
frequency The number of times a   particular item appears in a data set.  
frequency table A data listing which also   lists the frequencies of the data.  
     
G    
     
graph A type of drawing used to   represent data.  
greatest common factor (GCF) The largest number that   divides two or more numbers evenly.  
     
H    
     
horizontal A line with zero slope.  
hypotenuse   The side opposite the right   angle in a right triangle.  
     
I    
     
identity property of addition The sum of any number and 0   is that number.  
identity property of multiplication The product of 1 and any   number is that number.  
improper fraction A fraction with a numerator   that is greater than the denominator.  
independent events Two events in which the   outcome of the second is not affected by the outcome of the first.  
inequality A mathematical expression   which shows that two quantities are not equal.  read this
infinity A limitless quantity.  
inscribed angle An angle placed inside a   circle with its vertex on the circle and whose sides contain chords of the   circle.  
inscribed polygon A polygon placed inside a   circle so that each vertex of the polygon touches the circle.  
interval notation    read this
integers The set of numbers   containing zero, the natural numbers, and all the negatives of the natural   numbers.  
intercept The x-intercept of a line or   curve is the point where it crosses the x-axis, and the y- intercept of a   line or curve is the point where it crosses the y-axis.  
intercepted arc The arc of a circle within   an inscribed angle.  
interpolation A method for estimating   values that lie between two known values.  
intersecting lines Lines that have one and only   one point in common.  
inverse Opposite. -5 is the additive   inverse of 5, because their sum is zero. 1/3 is the multiplicative inverse of   3, because their product is 1.  
inverse operations Two operations that have the   opposite effect, such as addition and subtraction.  
irrational number A number that cannot be   expressed as the ratio of two integers.  
isosceles triangle A triangle with at least two   equal sides.  
     
L    
     
least common denominator The smallest multiple of the   denominators of two or more fractions.  
least common multiple The smallest nonzero number   that is a multiple of two or more numbers.  
like fractions Fractions that have the same   denominator.  
line A straight set of points   that extends into infinity in both directions.  
line of symmetry Line that divides a   geometric figure into two congruent portions.  
line   segment Two points on a line, and   all the points between those two points.  
locus A path of points.  
logic The study of sound   reasoning.  
lowest   terms Simplest form; when the GCF   of the numerator and the denominator of a fraction is 1.  
     
M    
     
mean In a data set, the sum of   all the data points, divided by the number of data points; average.  
median The middle number in a data   set when the data are put in order; a type of average.  
midpoint A point on a line segment   that divides the segment into two congruent segments.  
mixed   number A number written as a whole   number and a fraction.  
mode A type of average; the   number (or numbers) that occurs most frequently in a set of data.  
multiple A multiple of a number is   the product of that number and any other whole number. Zero is a multiple of   every number.  
multiplicative identity The number 1 is the   multiplicative identity because multiplying 1 times any number gives that   number.  
multiplicative inverse The reciprocal of a number.  
mutually exclusive events Two or more events that   cannot occur at the same time.  
     
N    
     
natural numbers The counting numbers.  
negative number A real number that is less   than zero.  
normal Perpendicular.  
number   line A line on which every point   represents a real number.  
numerator The top part of a fraction.  
     
O    
     
obtuse   angle An angle whose measure is   greater than 90 degrees.  
obtuse triangle A triangle with an obtuse   angle.  
octagon A polygon with 8 sides.  
odd   number A whole number that is not   divisible by 2.  
operation Addition, subtraction,   multiplication, and division are the basic arithmetic operations.  
opposites Two numbers that lie the   same distance from 0 on the number line but in opposite directions.  
ordered   pair Set of two numbers in which   the order has an agreed-upon meaning, such as the Cartesian coordinates (x,   y), where the first coordinate represents the horizontal position, and the   second coordinate represents the vertical position.  
origin The point (0, 0) on a   coordinate plane, where the x-axis and the y-axis intersect.  
outcome In probability, a possible   result of an experiment.  
     
P    
     
parallel Two lines are parallel if   they are in the same plane and never intersect.  
parallelogram A quadrilateral with   opposite sides parallel.  
pentagon A five-sided polygon.  
percent A fraction, or ratio, in   which the denominator is assumed to be 100. The symbol % is used for percent.    read here
perimeter The sum of the lengths of   the sides of a polygon.  
permutation A way to arrange things in   which order is important.  
perpendicular Two lines are perpendicular   if the angle between them is 90 degrees.  
pi The ratio of the   circumference of a circle to its diameter.  
plane A flat surface that   stretches into infinity.  
point A location in a plane or in   space, having no dimensions.  
polygon A closed plane figure made   up of several line segments that are joined together.  
polyhedron A three-dimensional solid   that is bounded by plane polygons.  
positive number A real number greater than   zero.  
power A number that indicates the   operation of repeated multiplication.  
prime   number A number whose only factors   are itself and 1.  
probability For an experiment, the total   number of successful events divided by the total number of possible events.  
product The result of two numbers   being multiplied together.  
proper fraction A fraction whose numerator   is less than its denominator.  
proportion An equation of fractions in   the form: a/b = c/d  
protractor a/b = c/d  
pyramid A device for measuring   angles.  
Pythagorean Theorem The theorem that relates the   three sides of a right triangle: a2+b2=c2      
     
Q    
     
quadrant One of the quarters of the   plane of the Cartesian coordinate system  
quadrilateral A polygon with 4 sides.  
quotient   The answer to a division   problem.  
     
R    
     
radius The distance from the center   to a point on a circle; the line segment from the center to a point on a   circle.  
range In statistics, the   difference between the largest and the smallest numbers in a data set.  
rate A ratio that compares   different kinds of units.  
ratio A pair of numbers that   compares different types of units.  
rational number A number that can be   expressed as the ratio of two integers.  
ray part of a line, with one   endpoint, and extending to infinity in one direction.  
real   numbers The combined set of rational   numbers and irrational numbers.  
reciprocal The number which, when   multiplied times a particular fraction, gives a result of 1.  
rectangle A quadrilateral with four   90-degree angles.  
reflection A transformation resulting   from a flip.  
regular polygon A polygon in which all the   angles are equal and all of the sides are equal.  
repeating decimal A decimal in which the   digits endlessly repeat a pattern.  
rhombus A parallelogram with four   equal sides.  
right   angle An angle whose measure is 90   degrees.  
right triangle A triangle that contains a   right angle.  
root The root of an equation is   the same as the solution to the equation.  
rotation A transformation in which a   figure is rotated through a given angle, about a point.  
     
S    
     
sample   space For an experiment, the   sample space includes all the possible outcomes.  
scale drawing A drawing that is a   reduction or enlargement of the original.  
scalene triangle A triangle with three   unequal sides.  
scattergram A graph with points plotted   on a coordinate plane.  
scientific notation A method for writing   extremely large or small numbers compactly in which the number is shown as   the product of two factors.  
set A well-defined group of   objects.  
similar Two polygons are similar if   their corresponding sides are proportional.  
simplifying Reducing to lowest terms.  
skew   lines Lines that are not in the   same plane and that do not intersect.  
slope The steepness of a line   expressed as a ratio, using any two points on the line.  
solution The value of a variable that   makes an equation true.  
sphere A three-dimensional figure   with all points in space a fixed distance from a given point, called the   center.  
square A quadrilateral with four   equal sides and four 90 degree angles.  
square   root The square root of x is the   number that, when multiplied by itself, gives the number, x.  
statistics The science of collecting,   organizing, and analyzing data.  
stem and leaf plot A technique for organizing   data for comparison.  
straight angle An angle that measures 180   degrees.  
supplementary angles Two angles are supplementary   if their sum is 180 degrees.  
surface   area For a three-dimensional   figure, the sum of the areas of all the faces.  
     
T    
     
terminating decimal A fraction whose decimal   representation contains a finite number of digits.  
translation A transformation, or change   in position, resulting from a slide with no turn.  
transformation A change in the position,   shape, or size of a geometric figure.  
transversal A line that intersects two   other lines.  
trapezoid A quadrilateral that has   exactly two sides parallel.  
tree   diagram A diagram that shows   outcomes of an experiment.  
triangle   A three-sided polygon.  
     
U    
     
unit   price Price per unit of measure.  
     
V    
     
variable A letter used to represent a   number value in an expression or an equation.  
vertex The point on an angle where   the two sides intersect.  
vertical angles A pair of opposite angles   that is formed by intersecting lines.  
volume   A measurement of space, or   capacity.  
     
W    
     
whole numbers The set of numbers that   includes zero and all of the natural numbers.  
     
X    
     
x-axis   The horizontal axis in a   Cartesian coordinate plane.  
x-intercept   The value of x at the point   where a line or curve crosses the x-axis.  
     
Y    
     
y-axis   The vertical axis in a   Cartesian coordinate system.  
y-intercept   The value of y at the point   where a curve crosses the y-axis.  
     
Z    
     
zero The additive identity; the   number that, when added to another number n, gives n.  
zero property of multiplication The product of zero and any   number is zero.