Hence the arc drawn from the vertex of an isosceles spherical triangle, to the middle of the base, is perpendicular to the base, and bisects the vertical angle. A Geometry for Beginners - Page 84by George Anthony Hill - 1880 - 314 pagesFull view - About this book
| Thomas Keith - Navigation - 1810 - 478 pages
...equilateral triangle is likewise equiangular, and the contrary. (I) COROLLARY III. A line drawn from the vertex of an isosceles triangle to the middle of the base, is perpendicular to, the base. For the two sides FB and BC are equal to the two sides FA and AC, and the angle FBC is equal to the... | |
| Adrien Marie Legendre - Geometry - 1819 - 574 pages
...the angle BDA — ADC ; therefore these two last are right angles. Hence, a straight line drawn from the vertex of an isosceles triangle, to the middle of the base, is perpendicular to that base, anil divides the vertical angle into two equal parts. In a triangle that is not isosceles,... | |
| Peter Nicholson - Architecture - 1823 - 210 pages
...Hence every equilateral triangle is also equiangular. 62. COROLLARY 2. — A straight line drawn from the vertex of an isosceles triangle to the middle of the base will bisect the vertical angle, and be perpendicular to the base. THEOREM 12. 63. If two angles of... | |
| Adrien Marie Legendre, John Farrar - Geometry - 1825 - 280 pages
...that the angle BDA = ADC ; therefore these two last are right angles. Hence a straight line drawn from the vertex of an isosceles triangle, to the middle of the base, is perpendicular to that base, and divides the vertical angle into two equal parts. In a triangle that is not isosceles,... | |
| Adrien Marie Legendre, John Farrar - Geometry - 1825 - 294 pages
...that the angle BDA = ADC; therefore these two last are right angles, /fence a straight line drawn from the vertex of an isosceles triangle, to the middle of the base, is perpendicular to that base, and divides the vertical angle into two equal parts. In a triangle that is not isosceles,... | |
| Thomas Keith - Navigation - 1826 - 504 pages
...equilateral triangle is likewise equiangular, and the contrary. (I) COROLLARY III. A line drawn from the vertex of an isosceles triangle to the middle of the base, is perpendicular to the base. For the two sides FB and вс are equal to the two sides FA and AC, and the angle FBC is equal to the... | |
| James Hayward - Geometry - 1829 - 218 pages
...will be equal (41), and AB and AC will therefore be equal ; and AG will be a straight line drawn from the vertex of an isosceles triangle to the middle of the base ; that is — BC is perpendicular to the oblique line AG, when it is perpendicular to the straight... | |
| Benjamin Peirce - Geometry - 1837 - 216 pages
...right angle ; and also DAB = DAC, that . is> The arc, drawn from the vertex of an isosceles spherical triangle to the middle of the base, is perpendicular...to the base, and bisects the angle at the vertex. 454. Corollary. An equilateral spherical triangle is also equiangular. 455. Theorem. If two angles... | |
| Thomas Keith - 1839 - 498 pages
...equilateral triangle is likewise equiangular, and the contrary. (315) COROLLARY III. A line drawn from the vertex of an isosceles triangle to the middle of the base, is perpendicular to the base. For the two sides FB and BC are equal to the two sides FA and AC, and the angle FBC is equal, to the... | |
| Adrien Marie Legendre - Geometry - 1841 - 288 pages
...the anglf BDA = ADC ; therefore these two last are right angles. Hence a straight line, drawn from the vertex of an isosceles triangle to the middle of the base, is perpendicular to that base, and divides the vertical angle into two equal parts. In a triangle that is not isosceles,... | |
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