R
Radical
An expression such as
square root..
Radius
A line segment joining any
point on a circle or sphere to the center.
Also the length of that segment.
Random
variable A variable whose
value is determined by the outcome of a random experiment.
Range
The difference between
the greatest and the least numbers in a set of data.
Rate A
ratio that compares quantities of different kinds of units.
Ratio
0 An indicated quotient of two
numbers.
Ray A
part of a line with one endpoint.
Real
number Any number that is
either a rational number or an irrational number.
Reciprocals
Two numbers whose product
is 1.
Rectangle
A quadrilateral with four right
angles.
Rectangular
prism A prism of which all the faces are rectangles
Regular
polygon A polygon in
which all sides are congruent and all angles are congruent.
Reflection:
A mirror image of a figure across a line of symmetry.
Relation
A set of ordered pairs.
Relatively
prime numbers Two or more numbers that have no other common factor but 1.
Remainder
The last difference obtained in the division process
Repeating
decimal A decimal numeral in which a digit or series of digits other than
zero repeat forever in the
same
pattern
Rhombus
A parallelogram in which all
sides are congruent.
Right
angle An angle with
measure 90°.
Right
prism A solid with bases that are congruent polygons which lie in parallel
planes and are perpendicular
to
the lateral faces (sides) of the prism
Right
triangle A triangle with a
right angle.
Rigid
motions Motions such as
rotation, translation, and reflection, used to move a figure to a new position
without
Roster
method Defining or listing a set by naming the set with a capital letter,
and naming the elements within
a
pair of braces
Rounding
Writing a number to a certain approximation