 | Adrien Marie Legendre - 1841 - 288 pages
...BAD = DAC, and that 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,... | |
 | Benjamin Peirce - 1847 - 204 pages
...right angle ; and also DAIi = 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. 455. Corollary. An equilateral spherical triangle is also equiangular.... | |
 | Elias Loomis - 1849 - 252 pages
...the last two angles is a right angle. 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. PROPOSITION XVII. THEOREM. In a spherical triangle, the greater side... | |
 | 1851 - 716 pages
...is known that every line hanging plumb must be perpendicular to a horizontal plane, and that a line from the vertex of an isosceles triangle to the middle of the base, will be perpendicular to the base. Upon these principles rests the determination of a horizontal position... | |
 | Johann Georg Heck - 1851 - 712 pages
...is known that every line hanging plumb must be perpendicular to a horizontal plane, and that a line from the vertex of an isosceles triangle to the middle of the base, will be perpendicular to the base. Upon these principles rests the determination of a horizontal position... | |
 | Adrien Marie Legendre - 1852 - 436 pages
...that is to say, has all its angles equal. ADC; hence, tlie latter two are right angles. Therefore, the line drawn from the vertex of an isosceles triangle to the middle point of the base, divides the angle at the vertex into two equal parts, and is perpendicular to the... | |
 | Charles Davies - 1854 - 436 pages
...is equal to DAC, and BDA to 30 GEOMETRY. ADC; hence, the latter two are right angles. Therefore, ike line drawn from the vertex of an isosceles triangle to the middle point of the base, div1des the angle at the vertex into two equal parts, and is perpendicular to the... | |
 | Peter Nicholson - 1856 - 518 pages
...1. — Hence every equilateral triangle is also equiangular. в с 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... | |
 | Elias Loomis - 1858 - 256 pages
...the last two angles is a right angle. 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. In a spherical triangle, the greater side is opposite the greater angle,... | |
 | Johann Georg Heck - 1860 - 332 pages
...is known that every line hanging plumb must be perpendicular to a horizontal plane, and that a line from the vertex of an isosceles triangle to the middle of the base, will be perpendicular to the base. Upon these principles rests the determination of a horizontal position... | |
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Consequently, a line drawn from the vertex of an isosceles triangle to the middle of the base, bisects the vertical angle, and is perpendicular to the base. 
