 | John Playfair - 1836 - 148 pagine
...FC, that is, FC is perpendicular to DE. Therefore, if a straight line, &c. QED CGE PROP.. XI. 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... | |
 | Euclid, James Thomson - 1837 - 410 pagine
...semicircle is acute, and an angle in a 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... | |
 | John Playfair - 1837 - 332 pagine
...perpendicular to DE ; FC is therefore perpendicular to DE. 74 N PROP. XIX. THEOR. If a. straight linf 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 - 1837 - 112 pagine
...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... | |
 | Andrew Bell - 1837 - 290 pagine
...; that is, FC is perpendicular to DE. PROPOSITION XIX. THEOREM. If a straight line be a tangent to a circle, and from the point of contact a straight line be drawn perpendicular to the tangent, the centre of the circle shall be in that line. Let the straight line... | |
 | Euclides - 1838 - 264 pagine
...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 pagine
...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 pagine
...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 pagine
...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 pagine
...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... | |
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If a straight line touch a circle, and from the point of contact a straight line be drawn cutting the circle, the angles which this line makes with the line touching the circle, shall be equal to the angles which are in the alternate segments of the circle. 
