 | Euclid, Thomas Tate - 1849 - عدد الصفحات: 120
...perpendicular to DE. Therefore, if D 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. Let the straight... | |
 | Euclides - 1853 - عدد الصفحات: 146
...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... | |
 | Royal Military Academy, Woolwich - 1853 - عدد الصفحات: 400
...that is, FC is perpendicular to DE. Therefore, if a straight line, etc. QED PROPOSITION 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 - 1853 - عدد الصفحات: 334
...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 - عدد الصفحات: 176
...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 - عدد الصفحات: 176
...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 - عدد الصفحات: 534
...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 - عدد الصفحات: 334
...; 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 - عدد الصفحات: 1050
...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 - عدد الصفحات: 270
...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... | |
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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. 
