Elements of Geometry and Trigonometry from the Works of A.M. Legendre: Revised and Adapted to the Course of Mathematical Instruction in the United States |
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Page 20
... drawn . 12. A straight line is the shortest distance between two points . 13. Through the same point , only one straight line can be drawn which shall be parallel to a given line . 14. Magnitudes , which being applied the one to the ...
... drawn . 12. A straight line is the shortest distance between two points . 13. Through the same point , only one straight line can be drawn which shall be parallel to a given line . 14. Magnitudes , which being applied the one to the ...
Page 21
... drawn perpendicular to AB : then , ACE ECB two right + angles ( D. 13 ) . * But ECB is equal to ECD + DCB ( A. 9 ) : hence , ACE ECD + DCB = two right angles . E D But ACE + ECD A- -B But ACE + ECD = ACD ( A. 9 ) : there- fore , ACD + ...
... drawn perpendicular to AB : then , ACE ECB two right + angles ( D. 13 ) . * But ECB is equal to ECD + DCB ( A. 9 ) : hence , ACE ECD + DCB = two right angles . E D But ACE + ECD A- -B But ACE + ECD = ACD ( A. 9 ) : there- fore , ACD + ...
Page 22
... drawn , making with AC , the right angle ACF . Now , since ACD is a straight line , the angle FCD will be a right angle ( P. I. , C. 1 ) : and since ACE is a straight line , the angle FCE will also be a right angle . Hence , the angle ...
... drawn , making with AC , the right angle ACF . Now , since ACD is a straight line , the angle FCD will be a right angle ( P. I. , C. 1 ) : and since ACE is a straight line , the angle FCE will also be a right angle . Hence , the angle ...
Page 26
... drawn to the extremities of either side , their sum will be less than that of the two remaining sides of the triangle . Let O be any point within the triangle BAC , and let the lines OR , OC , be drawn to the extremities of either side ...
... drawn to the extremities of either side , their sum will be less than that of the two remaining sides of the triangle . Let O be any point within the triangle BAC , and let the lines OR , OC , be drawn to the extremities of either side ...
Page 30
... drawn from the vertex of an isosceles triangle to the middle point of the base , divides the angle at the vertex ... draw CD . Now , in the two triangles BDC , BAC , we have BD = AC , by construction ; the angle B equal to the angle ACB ...
... drawn from the vertex of an isosceles triangle to the middle point of the base , divides the angle at the vertex ... draw CD . Now , in the two triangles BDC , BAC , we have BD = AC , by construction ; the angle B equal to the angle ACB ...
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Common terms and phrases
adjacent angles altitude angle ACB angle BAD base ABCD bisect centre chord circ circumference circumscribed common comp cone consequently convex surface cosine Cotang cylinder diagonal diameter distance divided draw drawn edges equations equivalent feet figure find the area frustum given angle given line given point gles greater hence homologous homologous sides hypothenuse included angle inscribed circle intersect less Let ABC let fall logarithm magnitudes measured by half middle point number of sides oblique lines opposite parallelogram parallelopipedon pendicular perimeter perpendicular plane MN polyedral angle polyedron PROBLEM PROPOSITION pyramid quadrant radii radius ratio rectangle regular polygon right angles right-angled triangle Scholium secant segment side BC similar sine slant height solidity sphere spherical polygon spherical triangle square described straight line Tang tangent THEOREM triangle ABC triangular prism triedral angles vertex vertices
Popular passages
Page 27 - If two triangles have two sides of the one equal to two sides of the...
Page 227 - A spherical triangle is a portion of the surface of a sphere, bounded by three arcs of great circles.
Page 256 - The logarithm of . the quotient of two numbers, is equal to the logarithm of the dividend diminished by the logarithm of the divisor.
Page 97 - The square described on the hypothenuse of a right-angled triangle is equivalent to the sum of the squares described on the other two sides.
Page 26 - The sum of any two sides of a triangle is greater than the third side.
Page 271 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees...
Page 93 - The area of a parallelogram is equal to the product of its base and altitude.
Page 358 - CUBIC MEASURE 1728 cubic inches = 1 cubic foot 27 cubic feet = 1 cubic yard...
Page 323 - A'B'C', and applying the law of cosines, we have cos a' = cos b' cos c' + sin b' sin c' cos A'. Remembering the relations a' = 180° -A, b' = 180° - B, etc. (this expression becomes cos A = — cos B cos C + sin B sin C cos a.
Page 64 - Two equal chords are equally distant from the centre ; and of two unequal chords, the less is at the greater distance from the centre.