The Elements of EuclidDesilver, Thomas, 1838 - 416 páginas |
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Página 6
... perpendicular to it . XI . An obtuse angle is that which is greater than a right angle . XII . An acute angle is that which is less than a right angle . XIII . " A term or boundary is the extremity of any thing . " XIV . A figure is ...
... perpendicular to it . XI . An obtuse angle is that which is greater than a right angle . XII . An acute angle is that which is less than a right angle . XIII . " A term or boundary is the extremity of any thing . " XIV . A figure is ...
Página 17
... perpendicular to it ; therefore from the given point Ca perpendicular CH has been drawn to the given straight line AB . Which was to be done . PROP . XIII . THEOR . THE angles which one straight line makes with another upon the one side ...
... perpendicular to it ; therefore from the given point Ca perpendicular CH has been drawn to the given straight line AB . Which was to be done . PROP . XIII . THEOR . THE angles which one straight line makes with another upon the one side ...
Página 49
... perpendicular and the obtuse angle . Let ABC be an obtuse angled triangle , having the obtuse angle ACB , and from the point A let AD be drawn ( 12. 1 , ) perpendicular to BC produced : the square of AB is greater than the squares of AC ...
... perpendicular and the obtuse angle . Let ABC be an obtuse angled triangle , having the obtuse angle ACB , and from the point A let AD be drawn ( 12. 1 , ) perpendicular to BC produced : the square of AB is greater than the squares of AC ...
Página 50
... perpendicular to BC ; then is BC the straight line between the perpendicular and the acute angle at B ; and it is manifest that the square of AB , BC are equal ( 47. 1. ) to the square of AC and twice the square of BC . Therefore , in ...
... perpendicular to BC ; then is BC the straight line between the perpendicular and the acute angle at B ; and it is manifest that the square of AB , BC are equal ( 47. 1. ) to the square of AC and twice the square of BC . Therefore , in ...
Página 52
... perpendicular falls , is said to be farther from the centre . VI . A segment of a circle is the figure con- tained by a straight line and the cir- cumference it cuts off . VII . " The angle of a segment is that THE ...
... perpendicular falls , is said to be farther from the centre . VI . A segment of a circle is the figure con- tained by a straight line and the cir- cumference it cuts off . VII . " The angle of a segment is that THE ...
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Términos y frases comunes
altitude angle ABC angle BAC base BC BC is equal BC is given bisected centre circle ABCD circumference cone cylinder demonstrated described diameter draw drawn equal angles equiangular equimultiples Euclid ex æquali excess fore given angle given in magnitude given in position given in species given magnitude given ratio given straight line gles gnomon greater join less Let ABC multiple parallel parallelogram parallelogram AC perpendicular point F polygon prism proportionals proposition pyramid Q. E. D. PROP radius ratio of AE rectangle CB rectangle contained rectilineal figure remaining angle right angles segment sides BA similar sine solid angle solid parallelopiped square of AC square of BC straight line AB straight line BC tangent THEOR triangle ABC triplicate ratio vertex wherefore
Pasajes populares
Página 34 - If a straight line be divided into any two parts, the squares of the whole line and of one of the parts are equal to twice the rectangle contained by the whole and that part, together with the square of the other part. Let the straight line AB be divided into any two parts at the point C : the squares of AB, BC shall be equal to twice the rectangle AB, BC, together with the square of AC.
Página 143 - Wherefore, in equal circles &c. QED PROPOSITION B. THEOREM If the vertical angle of a triangle be bisected by a straight line which likewise cuts the base, the rectangle contained by the sides of the triangle is equal to the rectangle contained by the segments of the base, together with the square on the straight line which bisects the angle.
Página 63 - The angle in a semicircle is a right angle; the angle in a segment greater than a semicircle is less than a right angle; and the angle in a segment less than a semicircle is greater than a right angle.
Página 246 - Again ; the mathematical postulate, that " things which are equal to the same are equal to one another," is similar to the form of the syllogism in logic, which unites things agreeing in the middle term.
Página 9 - If one side of a triangle be produced, the exterior angle is greater than either of the interior opposite angles.
Página 119 - If two triangles have one angle of the one equal to one angle of the other and the sides about these equal angles proportional, the triangles are similar.
Página 19 - 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.
Página 12 - To construct a triangle of which the sides shall be equal to three given straight lines ; but any two whatever of these lines must be greater than the third (20.
Página 78 - If two triangles have two angles of the one equal to two angles of the other, each to each, and one side equal to one side, viz. either the sides adjacent to the equal...
Página 131 - ... rectilineal figures are to one another in the duplicate ratio of their homologous sides.