| 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 - 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... | |
| 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 - 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... | |
| 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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