 | British Association for the Advancement of Science - 1858 - 670 σελίδες
...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... | |
 | Frederick Augustus Griffiths - 1859 - 426 σελίδες
...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... | |
 | Thomas Stantial - 1859 - 352 σελίδες
...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 - 1859 - 198 σελίδες
...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... | |
 | Elias Loomis - 1860 - 246 σελίδες
...regular hexagon inscribed in a circle whose center is O; then any side as AB will be equal to the vidius AO. Draw the radius BO. Then the angle A.OB is the...OA'B, OBA are together equal to two thirds of two right angles; and since AO is equal to BO, each of these angles is one third of two right angles. Hence... | |
 | Robert Potts - 1860 - 380 σελίδες
...CD. Then any two of its opposite angles shall together be equal to two right angles. Join AC, BD. And 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... | |
 | Elias Loomis - 1861 - 254 σελίδες
...is equal to the radius of thf circumscribed circle. BOOK VI. Draw Ihe radius BO. Then the angle \.OB is the sixth part of four right angles (Prop. II.,...part of two right angles. Also, because the three an- A gles of every triangle are equal to two right angles, the two angles OA'B, OBA are together equal... | |
 | Euclides - 1862 - 172 σελίδες
...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... | |
 | William Thomas Read - 1862 - 144 σελίδες
...proved may be obtained, which shows them to be true for any triangle. • We know (by Eu. 1, 32), that the three angles of every triangle are equal to two right angles ; therefore those of ABC are equal to two right angles ; and since B = 90°, therefore A + C = 90°,... | |
 | Euclides - 1864 - 448 σελίδες
...Then any two of its opposite angles shall together be equal to two right angles. c Join AC, BD. And 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... | |
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When you have proved that the three angles of every triangle are equal to two right angles... 
