338 Appendix C
exponent A small number written to the upper right of another number that tells how many of
that number should be multiplied together.
extended ratio Several related ratios condensed into one statement. The ratios a:b, b:c, and a:c
make the extended ratio a:b:c.
exterior angle The angle formed when one side of a triangle is extended.
extremes The first and last numbers of a proportion.
faces The polygons that connect to form a polyhedron.
factor Each number in a multiplication.
factor tree A method of finding the prime factorization of a number by starting with one factor
pair and then factoring each of those factors, continuing until no possible factoring remains.
fraction A symbol that represents part of a whole.
greatest common factor The greatest common factor of two numbers is the largest number
that is a factor of both.
hypotenuse In a right triangle, the side opposite the right angle.
improper fraction A fraction whose value is more than one. The numerator is larger than the
denominator.
inscribed A polygon is inscribed in a circle if each of its vertices lies on the circle.
inscribed angle An angle with its vertex on the circle and sides that are chords.
integers The set of numbers that includes all the positive whole numbers and their opposites,
the negative whole numbers, and zero.
interest Money you pay for the use of money you borrow, or money you receive because you’ve
put your money into a bank account or other investment.
interest rate The percent of the principal that will be paid in interest each year.
inverse operation An operation that reverses the work of another.
irrational numbers Numbers that cannot be written as the quotient of two integers.
isosceles trapezoid A trapezoid in which the nonparallel sides are the same length.
isosceles triangle A triangle with two sides that are the same length.
lateral area The total of the areas of the parallelograms surrounding the bases of a prism. The
area of the rectangle that forms the curved surface of a cylinder. The area of the slanted surface
of a pyramid or cone.