| Moses Wolcott Redding, Author of Guide to Mount Moriah - 1875 - 570 pages
...Geometry, Astronomy, and Mathematics. It is to him that the world is indebted for the discovery that **the three angles of a triangle are together equal to two right angles,** and that in any right angled triangle, the square formed on the hypothenuse is equal to the sum of... | |
| John Hall - 1875 - 428 pages
...an opinion as we please ; if we reject a fact, we only advertise our stupidity. If a man denies that **the three angles of a triangle are together equal to two right angles,** we can demonstrate the proposition. If he says that Brutus did not kill Csesar, we can open the books... | |
| Matthew R. Miller - 1876 - 276 pages
...probably a horrible Inquisition would have flourished for a century, founded on the question whether **the three angles of a triangle are together equal to two right angles.** I have had some knowledge by personal experience of the unfairness of Universalists in their arguments... | |
| Richard Wormell - 1876 - 268 pages
...XVIII. The exterior angle of any triangle is equal to the two interior and opposite angles together, and **the three angles of a triangle are together equal to two right angles.** Let А В С be a triangle of which А С D is the exterior angle ; then shall and Л С А В + ЛABC+... | |
| Francis Cuthbertson (geometer.) - 1876 - 102 pages
...is = the two angles BAC, ABC together. Wherefore if one side of a triangle &c. QED PROPOSITION XX. **The three angles of a triangle are together equal to two right angles.** Let ABC be a A. Then shall its three angles be together equal to two right angles. Produce BCtoD. Then... | |
| E. S. Burchett - 1876 - 188 pages
...study of Euclid should observe the following points, that may be culled from the First Book : — 1st. **The three angles of a triangle are, together, equal to two right angles,** invariably. 2nd. The triangle has the same number of equal sides that it has equal angles. 3rd. The... | |
| 1878 - 958 pages
...and as we do so we discover that they have certain properties involved in their very nature, and that **the three angles of a triangle are together equal to two right angles,** and that parallel lines cannot meet. The properties of the ellipse, as demonstrated by Apollonius,... | |
| Edward Harri Mathews - 1879 - 94 pages
...necessarily true as it stands ? Having completed the enunciation, prove the proposition. 3. Prove that **the three angles of a triangle are together equal to two right angles** ; and investigate the sum of the exterior angles of any plane convex polygon. 4. Show how to bisect... | |
| Aristotle, Walter Mooney Hatch - 1879 - 658 pages
...demonstrated as necessary ; if, for example, any one ' opines ' after a process of demonstration that ' the **angles of a triangle are together equal to two right angles,' the** opinion which he has is a neee*#ary truth. Other opinions are drawn from the senses, and hence some... | |
| Pupil teachers - 1880 - 1486 pages
...Proof.@Because the triangle ABD is equilateral, therefore the triangle ABD is equiangular (i. 5, Cor.) **the three angles of a triangle are together equal to two right angles** (i. 32), therefore the angle ABD is equal to a third of two right angles, that is, two-thirds of a... | |
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