ALTERNATE

(I.at. alternat us, chun. parts are said to be alternate « when one is placed upon the stem a little higher lower than the other; the word is chietly applied i and is used in distinction to opposite, in which parts arise the same plant on opposite sides of the stem. Alternate. (Geometry.) When two straight intersected by a third, the interior angles on the sides of the intersecting line are said to be alternate. Thus A M N ami M N D are a! a \fg p angles: and so also are B M N wi\ - M N C. If the two straight lines A 13 \. and C D be parallel, (he alternal V P glea are equal. In pi ternate terms are the first an and also the second and fourth terms of a proportion are said to be taken altemati alternation, when the second and third are made to Changs places; and it is a well known theorem, that a proportion.' among four quantities of the same kind is noi i by this change. Thus, if a: b:: c: d, ternately, a: c: b: d. [s. 51]