| Mrs. Lincoln Phelps - Physics - 1848 - 288 pages
...see a triangle marked out before us, and it is demonstrated by a train of geometrical reasoning, thai **the sum of the three angles is equal to two right angles,** we are as perfectly certain of the fact as if it had been proved by actual measurement. 22. Difference... | |
| Education - 1849
...greater angle ; and conversely, the greater angle is opposite to the greater side. 2. In every triangle **the sum of the three angles is equal to two right angles.** 3. Two equal chords are equally distant from the centre ; and of two unequal chord«, the less is at... | |
| Charles Davies - Trigonometry - 1849 - 359 pages
...to BAC: hence, DEH + BAC is equal to two right angles. PROPOSITION XXV. THEOREM. In every triangle **the sum of the three angles is equal to two right angles.** Let ABC be any triangle : then will the angle C + A + B be equal to two right angles. For, produce... | |
| Charles Davies - Geometry - 1850 - 216 pages
...of the two angles, A and C, is equal to the outward angle CBD (Ax. 1). THEOREM XVII. In any triangle **the sum of the three angles is equal to two right angles.** Let ABC be any triangle : then will the sum of the three angles C A+B+C=two right angles. For, let... | |
| CHARLES DAVIS, L.L. D. - 1850
...of the two angles, A and C, is equal to the outward angle CBD (Ax. 1). THEOREM XVII. In any triangle **the sum of the three angles is equal to two right angles.** Let ABC be any triangle: then will the sum of the three angles C A-{-B-}-C=z two right angles . For,... | |
| Sir Henry Edward Landor Thuillier - Surveying - 1851 - 718 pages
...triangle, if either acute angle be taken from 90°, the remainder will express the other acute angle. 4. **The sum of the three angles is equal to two right angles.** 5. The greater side is opposite the greater angle, and the less side to the less angle. 6. The sum... | |
| A. M. LEGENDRE - 1852
...to BAC: hence, DEH '+ BAC is equal .to two right angles. PROPOSITION XXV. THEOEEM. In every triangle **the sum of the three angles is equal to two right angles.** Let ABC be any triangle : then will the sum of the angles 0+A+B be equal to two right angles. For,... | |
| Charles Davies, Adrien Marie Legendre - Geometry - 1854 - 432 pages
...equal to BAC: hence, DEH+BAC is equal to two right angles. PROPOSITION XXV. THEOREM. In every triangle **the sum of the three angles is equal to two right angles.** Let ABC be any triangle : then will the sum of the angles C+A+B be equal to two right angles. For,... | |
| George Roberts Perkins - Geometry - 1860 - 443 pages
...as many right angles as the polygon has sides, wanting four right angles. Cor. I. In any triangle, **the sum of the three angles is equal to two right angles.** x Cor. II. If one angle of a triangle is a right angle, as in the case of a right-angled triangle (D.... | |
| Thomas Wharton Collens - Psychology - 1860 - 358 pages
...on the track, and could not have secured it. Take, for instance, the theorem : " In every triangle **the sum of the three angles is equal to two right angles,"** and see how many different facts must be brought to bear, and how many distinct definitions, axioms,... | |
| |