 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...  The Cambridge Examiner - Page 4061881Full view - About this book
 | Euclides - Euclid's Elements - 1837 - 112 pages
...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 - Euclid's Elements - 1837 - 290 pages
...; 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... | |
 | Robert Simson - Geometry - 1838 - 434 pages
...from the point of contact a straight line be drawn cutting the circle, the angles made by this line with the line touching the circle, shall be equal...which are in the alternate segments of the circle. Let the straight line EF touch the circle ABCD in B, and from the point B let the straight line BD... | |
 | Euclides - 1838 - 264 pages
...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... | |
 | Euclides - Geometry - 1841 - 378 pages
...two; and when the adjacent angles are equal, they are right* angles. »iol>ef. PROP. XXXII. THEOR. 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... | |
 | John Playfair - Euclid's Elements - 1842 - 332 pages
...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 pages
...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... | |
 | Education - 1844 - 688 pages
...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 of contact a straight line be drawn cutting the circle ; the angles which this line makes with the touching line, shall be equal to the... | |
 | John Playfair - Euclid's Elements - 1844 - 338 pages
...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 - Geometry - 1845 - 382 pages
...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... | |
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