Books Books The opposite angles of any quadrilateral figure described in a circle, are toe/ether equal to two right angles. Let ABCD be a quadrilateral figure in the circle ABCD : any two of its opposite angles are together equal to two right angles. Euclid in Paragraphs: The Elements of Euclid: Containing the First Six Books ... - Page 71
by Euclid - 1845 - 199 pages ## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

Euclid, John Playfair - Circle-squaring - 1819 - 348 pages
...triangles, the four oblique angles of whJrh are equal to the three angles of the triangle, therefore the three angles of every triangle are equal to two right angles. Q, ED Though this method of treating the subject is strictly demonstrative, ;yet, as the reasoning... ## The Elements of Euclid: Viz. the First Six Books, Together with the Eleventh ...

Euclid, Robert Simson - Geometry - 1821 - 514 pages
...PROP. XXII. THEOR. The opposite angles of any quadrilateral figure described in a circle, are together equal to two right angles. Let ABCD be a quadrilateral...because the three angles of every triangle are equal (32. 1.) to two right angles, the three angles of the triangle CAB, viz. the angles CAB, ABC, BCA are... ## A Treatise on the Elements of Algebra

Bewick Bridge - Algebra - 1821 - 227 pages
...180°. Thus, if the angle ACF is 40° 25' 35", its supplement FCB will be 139° 34' 25".* 6. The * Since the three angles of every triangle are equal to two right angles, or to 180°, it is evident that in a right-angled triangle the two acute angles must be together equal... ## A Search of Truth in the Science of the Human Mind, Part First, Volume 1

Frederick Beasley - Psychology - 1822 - 584 pages
...space included between three straight lines that cut each, ever lead us on to the conclusion, that the three angles of every triangle, are equal to two right angles? Does it at all enter into the inquiry? Does it form any part of the argument? A man might long enough... ## An Inquiry Into the Principles of the Distribution of Wealth Most Conducive ...

William Thompson - Economics - 1824 - 634 pages
...applied to one out of a class or of a thousand, not able to understand, when properly explained, that " the three angles. of every triangle are equal to two right angles." Till this fundamental error and vice in education, the presuming to teach opinions instead of truth,... ## An Outline of the History of the Church in the State of Kentucky, During a ...

Robert Hamilton Bishop - Kentucky - 1824 - 464 pages
...present comprehension, and its being contrary to the first principles of reason. The proposition that the three angles of every triangle are equal to two right angles, is one absolutely beyond the comprehension of the illiterate hushnndman; is it therefore not true!... ## A Popular Course of Pure and Mixed Mathematics ...: With Tables of ...

Peter Nicholson - Mathematics - 1825 - 372 pages
...Proposition XXII. Theorem. The opposite angles of any quadrilateral figure described in a circle, we together equal to two right angles. Let ABCD be a quadrilateral figure in die circle ABCD ; any tw» of its opposite angles are together equal to two right angles. Join AC,... ## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

Euclid, John Playfair - Euclid's Elements - 1826 - 326 pages
...in a eirele, are together equal to two right angles. LetABCDbe a quadrilateral figure in the eirele ABCD; any two of its opposite angles 'are together equal to two right angles. Join AC, BD. The angle CAB is equal (21. 3.) to the angle CDB, beeause they are iu the same segnent BADC, and the... ## Euclid's Elements of geometry, transl. To which are added, algebraic ...

Euclides - 1826 - 226 pages
...are equal to two right angles. " 32.i. it are equal* to two right angles ; join AD, вс. Therefore because the three angles of every triangle are equal to two right angles, the angles CAB, ABC, CBA, are equal to two right angles. But the Let ABDC be a circle, and ABDC a quadrilateral... 