| Euclides - 1853
...FC; that is 5. FC is perpendicular to DE. Therefore, if a straight line, &c. QED PROP. XIX. THEOREM. **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 - 1853
...touching lines are right angles, and therefore equal : which is impossible (Az. 9). PBOP. XIX. THEOE. **If a straight line touch a circle, and from the point of contact a straight line be drawn** at right angles to it : then the centre of the circle shall be in that line. Let DE touch the circle... | |
| Euclid - 1853 - 136 Seiten
...part ff the circumference for its base as an angle at the circumference. If a straight line touches **a circle, and from the point of contact a straight line be drawn cutting the circle.** They shall stand upon equal parts of the circumference, whether they be at the center or the circumfer... | |
| Euclides - 1853 - 147 Seiten
...e. Therefore, if a straight line, &c. QED PROPOSITION XIX. — 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. LET the straight... | |
| William Somerville Orr - 1854
...here only to avoid interruption in the numbering of the propositions. PROPOSITION XIX.— THEOREM. **If a straight line touch a circle, and from the point of contact a straight line be** draw» at right angles to the touching line, the centre of the circle shall be in that. lim. PROPOSITION... | |
| John Playfair - 1855 - 318 Seiten
...; and when the adjacent angles are equal, they are right anles. •T*"*'V i^ PROP. XXXII. THEOR. Jf **a straight line touch a circle, and from the point...straight line be drawn cutting the circle, the angles** made by this line with the lute which touches the circle, shall be equal to the angles in the alternate... | |
| Robert Potts - 1855
...as c is the Arithmetic, Geometric, or Harmonic mean between a and b. 6. If a straight line touches **a circle, and 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 to the angles which are in the... | |
| Euclides - 1855
...extremities, without producing it, by means of the first part of this proposition. PROP. XXXII. THE 0 В. E M. **If a straight line touch a circle, and from the point of contact a straight line** bе drawn cutting the circle • the. angles which this straight line makes with the tangent are equal... | |
| Euclides - 1856
...is less than a right angle, wherefore ADC is greater than a right angle. LXVII.— EUCLID III. 32. **If a straight line touch a circle and from the point...straight line be drawn cutting the circle, the angles** made by this line with the line touching the circle, are equal to the angles in the alternate segments... | |
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