Elements of Geometry and Trigonometry: From the Works of A.M. Legendre |
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Page 21
... intersect each other , they form four angles about the point of intersection , which have received different names , with respect to each other . are 1o . ADJACENT ANGLES those which lie on the same side of one line , and on opposite ...
... intersect each other , they form four angles about the point of intersection , which have received different names , with respect to each other . are 1o . ADJACENT ANGLES those which lie on the same side of one line , and on opposite ...
Page 23
... intersect in only one point . NOTE . The method of demonstration employed above , called the reductio ad absurdum . It consists in assuming an hypothesis which is the contradictory of the proposition to be proved , and then continuing ...
... intersect in only one point . NOTE . The method of demonstration employed above , called the reductio ad absurdum . It consists in assuming an hypothesis which is the contradictory of the proposition to be proved , and then continuing ...
Page 26
... intersection D ( P. III . , C. ) : hence , the triangles coincide throughout , and are therefore equal in all their parts ( I. , D. 14 ) ; which was to be proved . PROPOSITION VII . THEOREM . The sum of any two sides of a triangle is ...
... intersection D ( P. III . , C. ) : hence , the triangles coincide throughout , and are therefore equal in all their parts ( I. , D. 14 ) ; which was to be proved . PROPOSITION VII . THEOREM . The sum of any two sides of a triangle is ...
Page 37
... intersection have different names , with respect to each other . F 1o . INTERIOR ANGLES ON THE SAME SIDE , are those that lie on the same side of the secant and within the other two lines . Thus , BGH and GHD are interior angles on the ...
... intersection have different names , with respect to each other . F 1o . INTERIOR ANGLES ON THE SAME SIDE , are those that lie on the same side of the secant and within the other two lines . Thus , BGH and GHD are interior angles on the ...
Page 39
... AGH are equal , because they are verti- cal angles ( P. II . ) ; and consequently , AGH and GHD are equal : hence , from Cor . 1 , AB and CD are parallel . PROPOSITION XX . THEOREM . If a straight line intersect BOOK I. 39.
... AGH are equal , because they are verti- cal angles ( P. II . ) ; and consequently , AGH and GHD are equal : hence , from Cor . 1 , AB and CD are parallel . PROPOSITION XX . THEOREM . If a straight line intersect BOOK I. 39.
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Common terms and phrases
AB² ABCD AC² adjacent angles altitude apothem Applying logarithms base and altitude bisect centre chord circle circumference circumscribed coincide cone consequently convex surface corresponding cosec cosine Cotang cylinder denote diagonals diameter difference distance divided draw drawn edges equally distant feet find the area Formula frustum given angle given straight line greater hence homologous hypothenuse included angle interior angles intersection less Let ABC log sin lower base mantissa measured by half number of sides opposite parallel parallelogram parallelopipedon perimeter perpendicular plane MN polyedral angle polyedron prism PROPOSITION proved pyramid quadrant radii radius rectangle regular polygons right angles right-angled triangle Scholium secant segment semi-circumference side BC similar sine slant height sphere spherical polygon spherical triangle square subtracted Tang tangent THEOREM triangle ABC triangular prisms triedral angle upper base vertex vertices whence
Popular passages
Page 126 - The square of the hypothenuse is equal to the sum of the squares of the other two sides ; as, 5033 402+302.
Page 59 - 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 18 - The circumference of every circle is supposed to be divided into 360 equal parts called degrees, and each degree into 60 equal parts called minutes, and each minute into 60 equal parts called seconds, and these into thirds, fourths, &c.
Page 104 - The square described on the hypothenuse of a rightangled triangle is equal to the sum of the squares described on the other two sides.
Page 6 - The logarithm of any power of a number is equal to the logarithm of the number multiplied by the exponent of the power.
Page 28 - If two triangles have two sides of the one equal to two sides of the...
Page 46 - All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides.
Page 99 - The area of a parallelogram is equal to the product of its base and altitude.
Page 172 - If two planes are perpendicular to 'each other, a straight line drawn in one of them, perpendicular to their intersection, will be perpendicular to the other.
Page 214 - A sphere is a solid bounded by a curved surface, every point of which is equally distant from a point within called the center.