 | 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... | |
 | 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... | |
 | 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... | |
 | John Fry Heather - Scientific apparatus and instruments - 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... | |
 | 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... | |
 | John Playfair - Euclid's Elements - 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... | |
 | 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.... | |
 | 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... | |
 | 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... | |
 | Euclides - 1862 - 140 pages
...semicircle, is less than a right angle. 13. 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.) 14. Therefore the angles ABC, ADC, are together equal to two right angles. 15. But the angle... | |
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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. 
