| Euclides - 1834 - 518 pàgines
...adjacent angles are equal, they are t right angles. f 10 Def. 1• PROPOSITION XXXII. ¥ THEOR. — 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 line touching the circle, shall be equal to the angles which are in... | |
| 1835 - 684 pàgines
...be perpendicular to the line touching the circle. Cor. 2. (Eue. iii. 19.) 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. Cor. 3. Tangents... | |
| 1836 - 488 pàgines
...is equal to the same two ; and when the adjacent angles are equal, they are right angles. XXXI. If a straight line touch a circle, and from the point...the angles in the alternate segments of the circle. XXXIV. If two straight lines within a circle cut one another, the rectangle contained by the segments... | |
| John Playfair - 1836 - 148 pàgines
...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 pàgines
...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 pàgines
...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... | |
| Andrew Bell - 1837 - 290 pàgines
...; 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 - 1837 - 112 pàgines
...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 pàgines
...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 pàgines
...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... | |
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