Least common denominator (LCD) - The least whole number which can be divided exactly (is divisible) by each of the denominators in a fraction addition or subtraction problem. Numerically equivalent to the least common multiple (LCM) of those denominators.
See Factor trees.
See also the explanation on Adding Large Fractions.

Least common multiple (LCM) - The least whole number (integer) which can be divided exactly (is divisible) by each of two or more given whole numbers. This is most easily done by by finding which prime factorization for each given number contains the greatest number of of each prime number and multiplying together the primes thus found. A check for having found the correct LCM is that the quotients found by dividing the LCM by the given numbers are relatively prime. A mnemonic (memory aid) for distinguishing GCF from LCM is that GCF uses the "Fewest" of each prime number while LCM uses the "Most."
See the explanations on Greatest Common Factor (GCF) and Least Common Denominator (LCD).

Leg - .

Legs of an isosceles triangle - .

Legs of a right triangle - .

Legs of a trapezoid - .

Length - .

Let - Given. See proof.

Like Terms - Terms with the variable(s) having the same name(s) raised to the same power(s). May be combined by adding their coefficients (coefficients may be negative. The powers do not change.

Limit - .

Line - A set of points of infinite length and occupying only one dimension. An infinitely long, infinitely thin, straight figure. See Line segment, Ray.

Line segment - A contiguous portion of a line, finite in length and terminated by two endpoints, one at each end. The distance between the endpoints is equal to the length of the segment. See Ray.

Linear - Forming a straight line. A characteristic of a first-order equation. The behavior of a direct variation or proportion.

Linear unit - .

Locus - A set of points located according to a rule (list, definition or formula). A figure. A shape.

Logarithm. - .

Last updated 6/2/97 - 3/20/2000.