Books Books
Proportional, when the ratio of the first to the second is equal to the ratio of the second to the third.
Elements of Geometry and Conic Sections - Page 37
by Elias Loomis - 1857 - 226 pages

## Lessons in Geometry: For the Use of Beginners

George Anthony Hill - Geometry - 1888 - 202 pages
...77. I. Define a proportion. Four quantities are said to be proportional, or to form a proportion, if the ratio of the first to the second is equal to the ratio of the third to the fourth. For example: since ^ = f, the numbers 4, 10, 2, 5, are proportional. A h EF CDGH...

## Lessons in Geometry: For the Use of Beginners

George Anthony Hill - Geometry - 1888 - 200 pages
...77. 1. Define a proportion. Four quantities are said to be proportional, or to form a proportion, if the ratio of the first to the second is equal to the ratio of the third to the fourth. For example: since T4T = ^, the numbers 4, 10, 2, 5, are proportional. ABEF CDGH...

## The Elements of Plane Geometry:pPart I(corresponding to Euclid Books I.-II ...

...consequents, £, Q. DEF. 7. Three magnitudes (A, £, C) of the same kind are said to be proportionals, -when the ratio of the first to the second is equal to that of the second to the third ; that is, when A: B :: B : C. In this case C is said to be the third...

William Frothingham Bradbury, Grenville C. Emery - Algebra - 1889 - 428 pages
...two terms together are called a couplet. 169. Proportion is an equality of ratios. Four numbers are proportional when the ratio of the first to the second is equal to the ratio of the third to the fourth. The equality of two ratios is indicated by the sign of equality (=) or by four...

## The Elements of Plane and Solid Geometry ...

Edward Albert Bowser - Geometry - 1890 - 414 pages
...EATIO AND PROPORTION. SIMILAE FIGURES. D'EFINITIOTSS. 277. Four quantities are said to be in proportion when the ratio of the first to the second is equal to the ratio of the third to the fourth. Thus, if £ = ° then, A, B, C, D are said to be in proportion. The proportion...

## The Elements of Plane and Solid Geometry: With Numerous Exercises

Edward Albert Bowser - Geometry - 1891 - 424 pages
...KATIO AND PKOPOKTION. SIMILAR FIGUKES. DEFINITIONS. 277. Four quantities are said to be in proportion when the ratio of the first to the second is equal to the ratio oi the third to the fourth. Thus, if g = g, then, A, B, C, D are said to be in proportion. The proportion...

## The Principles of Elementary Algebra

Nathan Fellowes Dupuis - Algebra - 1892 - 362 pages
...quantity. PROPORTION. 82. Pour quantities are proportional, or are in proportion, or form a proportion, when the ratio of the first to the second is equal to the ratio of the third to the fourth. Thus a, b, c, d are proportional when a : b •— с : d. This may be expressed...

## The Elements of Euclid: Viz. the First Six Books, Together with the Eleventh ...

Euclid - Geometry - 1892 - 518 pages
...: A is the reciprocal of A : B. g. Three magnitudes of the same kind are said to be proportionals, when the ratio of the first to the second is equal to that of the second to the third. Thus A, B, C are proportionals if • A : B :: B : C. B is called...