 30. A straight line drawn from the vertex of an isosceles triangle to the middle of the base is perpendicular to the base. Find the area of a regular pentagon whose sides are 24", if the radius of the circle drawn around the  Book III - Page 223by George William Myers - 1908Full view - About this book
 | 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.... | |
 | Thomas Keith - 1839 - 498 pages
...Hence every equilateral triangle is likewise equiangular, and the contrary. (315) COROLLARY III. A line drawn from the vertex of an isosceles triangle...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 - 1839 - 372 pages
...the angle BAD, is equal to DAC, and BDA to ADC, hence the latter two are right angles; therefore, the line drawn from the vertex of an isosceles triangle to the middle point of its base, is perpendicular to the base, and divides the angle at the vertex into two equal... | |
 | Geometry - 1843 - 376 pages
...the angle BAD, is equal to DAC, and BDA to ADC, hence the latter two are right angles; therefore, the line drawn from the vertex of an isosceles triangle to the middle point of its base, is perpendicular to the base, and divides the angle at the vertex into two equal... | |
 | Euclides - 1845 - 546 pages
...triangle. Then AE' + BF'+GC' = BE' + CF* + AG*. Required a demonstration. 27. Prove that the square of any straight line drawn from the vertex of an isosceles triangle to the base, is less than the square of a side of the triangle by the rectangle contained by the segments... | |
 | Charles Davies - Trigonometry - 1849 - 372 pages
...angle BAD, is equal to DAC, and BDA to ADC, hence the latter two are right angles ; therefore, the line drawn from the vertex of an isosceles triangle to the middle point of its base, is perpendicular to the base, and divides the angle at the vertex into two equal... | |
 | Elias Loomis - Conic sections - 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. EBC, ACB are equal; hence the angle ECB is equal to the angle ABC (Prop.... | |
 | Euclides - 1850 - 350 pages
...equivalent to twice the rectangle under the extreme segments. III. 26. Prove that the square of any straight line drawn from the vertex of an isosceles triangle to the base, is less than the square of a side of the triangle by the rectangle contained by the segments... | |
 | Adrien Marie Legendre - Geometry - 1852 - 436 pages
...that is to say, has all its angles equal. ADO] hence, tlie latter two are right angles. Therefore, the line drawn from the vertex of an isosceles triangle to the middle point of the hase, divides the angle at the vertex into two equal parts, and is perpendicular to the... | |
 | Charles Davies - Geometry - 1854 - 436 pages
...that is to say, has all its angles equal. ADC] hence, the 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... | |
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