
Mathematical
"T" Words table An arrangement of data in rows and columns. Takeaway Model for Subtraction If a quantity y is taken away from an original quantity x with the same units, the quantity left is x  y. tangent
A line, ray, segment, or plane which intersects a curve or curved surface
in exactly one point. tangent
of an angle The
ratio (length of leg opposite to the angle/length of leg adjacent to the
angle) in a right triangle. Abbreviated tan. tangent circles Two circles that have exactly one point in common.
terminal
point
The endpoint of a vector. terminating decimal A decimal that ends. Also called finite decimal. terms Numbers or products of numbers and variables that are added.
tessellation
A filling up of a twodimensional space by congruent copies of a figure
that do not overlap. The figure which is copied is commonly called the
"fundamental region" tetrahedron
A polyhedron with four faces. theorem A statement deduced from postulates, definitions, or other previously deduced theorems. 306090
triangle
A triangle in which the three angles measure 30, 60, and 90. 3dimensional
coordinate system
A system of coordinates used to locate points in space by their distances
and directions from three mutually perpendicular lines. threedimensional
figure
A figure whose points do not all lie in a single plane. transformation The movement of a figure in a plane from its original position, the preimage, to a new position, the image. Also called a map. Transformations can occur when there is a reflection, a rotation, a translation, or a glide reflection of the original image. translation
A transformation in which every point
of the preimage moves in the same direction by the same amount to form
the image. A translation
is also referred to as a "slide". translation image The result of adding the same numbers to the coordinates of the points in a figure. In the drawing above, triangle A'B'C' is the translation image of triangle ABC. Also called slide image. transversal
A line that
intersects two or more lines. trapezoid
A quadrilateral
that has (at least) one pair of parallel sides.
traversable network A network in which all the arcs may be traced exactly once without picking up the tracing instrument.
trial and error A problemsolving strategy in which various solutions are tried until the correct solution is found. triangle A polygon with three sides. TriangleSum Property In any triangle, the sum of the measures of the angles is 180°. triangular region A triangle and the space inside it. triangulate
To split a polygon into nonoverlapping triangles. Triangulation is usually
used to help find the areas of polygons. trigonometric
ratio
A ratio of the lengths of the sides in a right triangle. trillion A word name for 1,000,000,000,000 . trillionth A word name for , or .00000 00000 01. trisect To divide into three congruent parts. truncate To cut off a number at a particular decimal place. Truncation does not mean that the decimal is rounded up, a part of it is simply cut off.
truth value The condition of a statement in logic; either true or false. turn A transformation in which every point of the preimage is rotated by a given angle about a point (in two dimensions) or a line (in three dimensions).They are also called rotations. A turn in the clockwise
direction is considered negative and one in the counterclockwise
direction is considered positive. twocolumn proof A form of written proof in which the conclusions are written in one column and the justifications are written beside them in a second column. EX: twodimensional Pertaining to figures that lie in a single plane, or to their geometry. This is "flat land" so to speak.
