The Facts On File Algebra Handbook

trapeziumA four-sided POLYGON(QUADRILATERAL) that has no parallel sides.
See alsoSECTION IV CHARTS AND TABLES.

trapezoidA four-sided POLYGON(QUADRILATERAL) that has only two
parallel sides.
See alsoSECTION IV CHARTS AND TABLES.

triangle APOLYGONthat has three sides and three ANGLEs. The SUMof the
angles always equals 180°.
See alsoSECTION IV CHARTS AND TABLES.

trinomialAPOLYNOMIALthat has exactly three TERMs. An EXPRESSIONthat
consists of a string of three MONOMIALs. For example, 4x+ 5y– 6x^2 y.
See alsoSECTION IV CHARTS AND TABLES.

unary One.

union Asolution SETthat includes all of the elements of each individual
set, and all of the elements of the combined sets. For example, if
A= {all EVEN NUMBERs between 0 and 10} and B= {all numbers
between 7 and 15}, then the union of Aand Bincludes all of the
even numbers between 0 and 10 and all numbers between 7 and

15. A union set is an inclusiveset of all of the elements. Union is
    identified with the symbol ∪.

trapezium – union GLOSSARY

trapezium – union GLOSSARY

Tetrahedron

Trapezium

Trapezoid

c

b a

C

A B

Triangle