Table - .

Tangent of an Angle - In a right triangle, for a given angle, the ratio of the length of the opposite leg (the side across from the measured angle) adjacent leg (the side next to the measured angle). See trigonometric function.

Tangent to a circle" - A line which intersects a coplanar circle at exactly one point. The tangent line is perpendicular to the diameter of the circle.

Tangent to a function" - A line which has the same slope as a function at the point of intersection.

Tens - Multiples of ten. The second place to the left of the decimal point.

Tenths - Multiples of one tenth. The first place to the right of the decimal point.

Term - A mathematical expression separated from other terms by an addition or subtraction symbol.

Then - The conclusion part of a conditional statement. The logical next step of a proof. See if, hypothesis.

Theorem - The conclusion of a mathematical proof. The proof itself. The results of a correctly written proof are valid (logically connected from beginning to end), but are not necessarily true. The truth of the conclusion depends on the truth of the assumptions ( given information, definitions, or axioms (not proved but assumed to be true) and theorems previously proved.

Total - The result of an addition operation. The entire amount. Sum. Transformation - A mapping of points or values into another set of points or values. Each point in the original set (pre-image or input) must map to exactly one point in the resulting set (image or output). Two or more pre-image points may map to the same point in the image but the result must be predictable. A relation with more than one output variable. See Function.

Transitive property - .

Translation - . See similarity transformation.

Transversal - A line which cuts across two other lines.

Trapezoid - A closed, four-sided, plane figure with exactly two parallel sides (bases). The area of a trapezoid is equal to the average of the bases multiplied by the height. The average of the bases is the length of the median.

Triangle - A polygon with three sides. A closed, plane figure formed by three line segments connected at their endpoints. The boundary of the intersections of the interior of three angles in a plane having each side collinear with one of the other angles but with rays pointing in opposite directions. The area of a triangle is half the product of the base times the altitude of a triangle">altitude (height).

Trigonometry - The study of the right triangle. In applications, the calculation of the length of a side of a right triangle given the measure of an angle and a side or, given the lengths of two sides, the measure of an angle. See trigonometric function.

Trigonometric function - The ratio of two sides of a right triangle for a given measure of a specified angle of the triangle. See trigonometry.

Trinomial - A polynomial with three terms. See the explanation on Factoring Polynomials.

Trivial - Too simple to be an effective part of a pattern.

True - .

Truth set - .

Last updated 6/2/97 - 5/4/2000.