Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Books Books
" ... the three angles of a triangle are together equal to two right angles, although it is not known to all. "
The Works of John Playfair ...: With a Memoir of the Author ... - Page 335
by John Playfair - 1822
Full view - About this book

The Western World; Or, Travels in the United States in 1846-47 ..., Volume 3

Alexander Mackay - 1850 - 394 pages
...they confined themselves to the teaching of such simple truths as that two and two make four, and that the three angles of a triangle are together equal to two right angles ? And what holds good of a branch of secular education, holds good of it in its entirety. If mathematics...
Full view - About this book

A Man

J. D. Bell - 1850 - 488 pages
...there are principles of numbers and of geometry, which will exist forever. Such is the truth, that the three angles of a triangle are together equal to two right angles. Such is the truth, that the square described on the hypothenuse of a right-angled triangle, is equal...
Full view - About this book

The Theory of Reasoning

Samuel Bailey - 1851 - 254 pages
...An exterior angle of a triangle is equal to both its opposite interior angles, and all the interior angles of a triangle are together equal to two right angles. The exterior angle BCD formed by the production of the side AC of the triangle ABC, is equal to the / \...
Full view - About this book

Bases of Belief, an Examination of Christianity as a Divine Revelation by ...

Edward Miall - 1853 - 464 pages
...which make their appeal to the intellect, without having within us a spark of spiritual life. That the three angles of a triangle are together equal to two right angles may be a truth in which the derived mind may meet the Uncreated Mind, without any conscious commingling...
Full view - About this book

The Portrait Gallery of Distinguished Poets, Philosophers ..., Volume 2

1853 - 530 pages
...advanced as far as the thirty-second proposition of the first book of Euclid. He had perceived that the three angles of a triangle are together equal to two right ones, and was searching for a satisfactory proof, when his father surprised him in his forbidden speculations....
Full view - About this book

Rational Psychology: Or, The Subjective Idea and the Objective Law of All ...

Laurens Perseus Hickok - 1854 - 726 pages
...originate phenomena. 3. Space and time have a necessity of being independently of all phenomena. — That the three angles of a ', -<* triangle are together equal to two right angles is a necessary and universal truth, but yet not independent. Provided the triangle be, then this truth...
Full view - About this book

Orr's Circle of the Sciences: Organic nature, vols. 1-3 (1854-1856)

William Somerville Orr - 1854 - 534 pages
...from the formula — sin. A sin. B ein. C abc without reference to Euclid's demonstration. Thus, since the three angles of a triangle are together equal to two right angles, we have A + В + С = 180°. .-. sin. (А + В) = sn. (180° — С) = sin. C. Л sin. A cos. B + sin....
Full view - About this book

A course of practical geometry for mechanics

William Pease - 1856 - 108 pages
...cannot be formed. This rule of comparison does not extend to the angles of a triangle ; for, since the three angles of a triangle are together equal to two right angles, or 180°; in a right-angled triangle, one angle (the right angle) is equal to the sum of the other...
Full view - About this book

The English Journal of Education, Volumes 11-13

1857 - 1266 pages
...given equiangular and equilateral hexagon. SECTION IV. — Show how to prove experimentally : 1. That the three angles of a triangle are together equal to two right angles. 2. That the square of the hypothenuse of a right angled triangle is equal to the sum of the squares...
Full view - About this book

The Pupil-teacher: A Monthly Journal of Practical Educational ..., Volume 3

1857 - 400 pages
...the Line of Direction to any point in the Base Line will be together equal to a right angle ; tecause the three angles of a triangle are together equal to two right angles. Hence the side at 30° to the perspective centre will make with •the Base Line an angle of 60°....
Full view - About this book




  1. My library
  2. Help
  3. Advanced Book Search
  4. Download EPUB
  5. Download PDF