| Charles Bonnycastle - Geometry - 1834 - 631 pages
...the latter will immediately follow from the principle already demonstrated, that in every triangle **the sum of the three angles is equal to two right angles.** For since the angle at C is a right angle, the sum of the remaining angles will be together equal to... | |
| Adrien Marie Legendre - Geometry - 1836 - 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 an- R glc C + A + B be equal to two right angles. For, produce... | |
| Adrien Marie Legendre - Mathematics - 1841 - 235 pages
...measure of the three angles of the triangle a'c'b', reduces itself to 2 D ; therefore, in any triangle, **the sum of the three angles is equal to two right angles.** 58. Corollary i. Two angles of a triangle being given, or only their sum, the third will be known by... | |
| Roswell Park - Best books - 1841 - 587 pages
...the greater angle : and either side is always less than the sum of the other two. In every triangle, **the sum of the three angles is equal to two right angles,** or 180°. When two triangles have the angles of the one equal to the corresponding angles of the other,... | |
| Charles Waterhouse - Arithmetic - 1842 - 166 pages
...triangle, that is the greater which is opposite to the greater side. , •• 4. In every triangle, **the sum of the three angles is equal to two right angles** ; in a square, there are four right angles, 5. The sum of all the interior angles of a polygon, is... | |
| Charles Waterhouse - Arithmetic - 1844 - 216 pages
...very unequal. PRINCIPLES. 1. In a square there are four right angles, or 360°. 2. In every triangle, **the sum of the three angles is equal to two right angles.** -3. In an isosceles triangle, the angles opposite to the equal sides are equal. 4. The sum of all the... | |
| 1845
...the three angles of the triangle ABC make up the same sum as the three angles CAB, BAE, EAD ; hence, **the sum of the three angles is equal to two right angles** (Prop. III.) Cor. 1. Two angles of a triangle being given, or merely their sum, the third will be found... | |
| Nathaniel Bowditch - 1846 - 451 pages
...the sum of the two angles EFG and EGF, and at the same time / XXXV. In any right-lined triangle, ABC, **the sum of the three angles is equal to two right angles.** To prove this, you must produce BC (in the fig. Art. 33) towards D; then(byw3rf.33), the external angle... | |
| Anthony Nesbit - Plane trigonometry - 1847 - 426 pages
...properties. 1. The greatest side is opposite the greatest angle, and least side opposite the least angle. 2. **The sum of the three angles is equal to two right angles,** or 180°. 3. If one angle be given, the sum of the other two is found by subtracting the given angle... | |
| Roswell Park - 1847
...the greater angle : and either side is always less than the sum of the other two. In every triangle, **the sum of the three angles is equal to two right angles,** or 180°. When two triangles have the angles of the one equal to the corresponding angles of the other,... | |
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