 | Euclides - 1837 - 112 pagina’s
...drawn from F, is _L DE. PROPOSITION XIX. (Argument ad absurdum). Theorem. If a straight line touches a circle, and from the point of contact a straight line be drawn at right angles to the touching line, the centre of the circle shall be in that line. x> cv, Suppose... | |
 | Euclides - 1838 - 264 pagina’s
...supposed to have been subjoined, not by Euclid, but by some one of the early editors. PROP. XIX. THEOR. If a straight line touch a circle, and from the point of contact a straight line be drawn at right angles to the touching line, the centre of the circle shall be in that line. Let the straight... | |
 | Robert Simson - 1838 - 434 pagina’s
...FC, that is, FC is perpendicular to DE. Therefore, if a straight line, &c. UED 0 PROP. XIX. THEOR. IF a straight line touch a circle, and from the point of contact a straight line be drawn at right angles to the touching line, the centre of the circle shall be in that line. Let the straight... | |
 | Euclides - 1841 - 378 pagina’s
...besides FC, that is, FC is perpendicular to DE. Therefore, if a straight line, &c. QED PROP. XIX. THEOR. If a straight line touch a circle, and from the point of contact a straight line be drawn at right angles to the touching line, the centre of the circle shall be in that line. and from C let... | |
 | John Playfair - 1842 - 332 pagina’s
...other line but FC can be perpendicular to DE ; FC is therefore perpendicular to DE. PROP. XIX. THEOR. If a straight line touch a circle, and from the point of contact a straight line be drawn at right angles to the touching line, the centre of the circle is in that line. Let the straight line... | |
 | Euclides - 1842 - 316 pagina’s
...perpendicular to DE. Therefore, if a straight line, &c. QED PROP. XIX. THEOR. IF a straight line touches a circle, and from the point of contact a straight line be drawn at right angles to the touching line, the centre of the circle shall be in that line. ELEMENTS Let... | |
 | 1844 - 688 pagina’s
...opposite angles of any quadrilateral inscribed in a circle, are together equal to two right angles. 11. If a straight line touch a circle, and from the point...straight line be drawn cutting the circle ; the angles which this line makes with the touching line, shall be equal to the angles in the alternate segments.... | |
 | John Playfair - 1844 - 338 pagina’s
...be perpendicular to DE ; FC is therefore perpendicular to DE. PROP. XIX. THEOR. If a straight lino touch a circle, and from the point of contact a straight line be drawn at right angles to the touching line, the centre of the circle is in that line, Let the straight line... | |
 | Euclid, James Thomson - 1845 - 382 pagina’s
...semicircle is acute, and an angle ma segment less than a semicircle is obtuse. PROP. XXXII. THEOR. — If a straight line touch a circle, and from the point of contact a straight line be drawn dividing the circle into two segments ; the angles made by this line with the tangent are equal to... | |
 | Euclid - 1845 - 218 pagina’s
...that is, FC is perpendicular to DE. Therefore, if a straight line, &c. QED PROPOSITION XIX. THEOB. — If a straight line touch a circle, and from the point of contact a straight line be drawn at right angles to the touching line, the centre of the circle shall be in that line. Let the straight... | |
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If a straight line touch a circle, and from the point of contact a... 
