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 ## Report of the Annual Meeting, Volume 27

British Association for the Advancement of Science. Meeting - Science - 1858 - 682 pages
...thereby with facility and despatch arriving at some novel and elegant conclusions. A Demonstration that the Three Angles of every Triangle are equal to Two Right Angles. By BA MURRAY. On the Surface of Centres of an Ellipsoid. By the Rev. G. SALMON, DD, MRIA LIGHT, OPTICAL... ## Report of the Annual Meeting

British Association for the Advancement of Science - Science - 1858 - 670 pages
...thereby with facility and despatch arriving at some novel and elegant conclusions. A Demonstration that the Three Angles of every Triangle are equal to Two Right Angles. By BA MURRAY. On the Surface of Centres of an Ellipsoid. By the Rev. G. SALMON, DD, MRLA. LIGHT, OPTICAL... ## A test-book for students; comprising sets of examination papers upon ...

Thomas Stantial - Examinations - 1859 - 356 pages
...and all the angles made by any number of lines meeting in a point are equal to four right angles. B. The three angles of every triangle are equal to two right angles. C. The angles at the base of an isosceles triangle are equal to one another. D. Construct a parallelogram... ## A Treatise on Mathematical Instruments: Including Most of the Instruments ...

John Fry Heather - Angles (Geometry) - 1859 - 198 pages
...the two angles HI A and '•A HAI; and because the vertical angles AVH and IVE are equal, and that the three angles of every triangle are equal to two right angles, therefore the two angles VIE and s EH are, together, equal to the two angles AH v and HAI, and therefore... ## The Artillerists̓ Manual, and British Soldiers̓ Compendium

Frederick Augustus Griffiths - Artillery - 1859 - 426 pages
...radii, its sides become the sines of the opposite angles, or the cosines of the adjacent augles. 5. The three angles of every triangle are equal to two right angles ; hence the obilque angles of a right-angled triangle are each other's complements. 6. The sum of the... ## Elements of Geometry: Containing the First Six Books of Euclid : with a ...

John Playfair - Geometry - 1860 - 332 pages
...ABC, ADC are equal to two right angles; in the same manner, the angles BAD, DCB may be shewn to be 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. COR. 1. If aii) side of a quadrilateral... ## Euclid's Elements of Geometry: Chiefly from the Text of Dr. Simson, with ...

Robert Potts - Geometry, Plane - 1860 - 380 pages
...XXII. THEOREM. The opposite angles of any quadrilateral figure inscribed in a circle, are together equal to two right angles, Let ABCD be a quadrilateral figure in the circle AB CD. Then any two of its opposite angles shall together be equal to two right angles. Join AC, BD.... ## Euclid's Elements of plane geometry [book 1-6] explicitly enunciated, by J ...

Euclides - 1860 - 288 pages
...than a semicircle, is less than a right angle. And because ABCD is a quadrilateral figure in a circle, any two of its opposite angles are together equal to two right angles (III. 22) ; therefore the angles ABC and ADC are equal to two right angles ; and ABC is less than a... ## The school Euclid: comprising the first four books, by A.K. Isbister

Euclides - 1862 - 172 pages
...snall be together equal to two right angles. CONSTRUCTION Draw the diagonals AC and DB. DEMONSTRATION Because the three angles of every triangle are equal to two right angles, (i. 32) the three angles of the triangle CAB, viz. the angles CAB, ABC, BCA, are equal to two right... 