| Henry William Watson - 1871 - 320 σελίδες
...triangles are equal in all respects, therefore DE is equal to DF, and ADE is equal to ADF. PROPOSITION 2I. If a straight line touch a circle and from the point of contact another straight line be drawn cutting the circle, the angles which the cutting line makes with the... | |
| Euclides, James Hamblin Smith - 1872 - 376 σελίδες
...are normals to the circle at the points where they meet the circumference. PROPOSITION 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 must be in that line. Let the st. line... | |
| Euclides - 1872 - 102 σελίδες
...circles touched by both lines lie in two lines at right angles to each other. PROPOSITION XIX. THEOREM. If a straight line touch a circle, and from the point of contact a straight line be draicn at right angles to the touching line, the centre of the circle must be in that line. Let the... | |
| Henry Major - 1873 - 588 σελίδες
...is equal to the same two ; and when the adjacent angles are equal, they are right angles. XXXII. — If a straight line touch a circle, and from the point of contact a straight line lie drawn meeting the circle, the angles which this line makes with the line touching the circle shall... | |
| Braithwaite Arnett - 1874 - 130 σελίδες
...double of the square on half the line, and of the square on the line between the points of section. 4. 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. Describe a circle... | |
| Euclides - 1874 - 342 σελίδες
...is, 5. FC is perpendicular to DE. Therefore, if a straight line, &c. QED PROPOSITION 19.— 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... | |
| Edward Atkins - 1874 - 428 σελίδες
...perpendicular to DE, but FC; therefore FC is perpendicular to DE. PROPOSITIONS. Proposition 19.— 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... | |
| Francis Cuthbertson - 1874 - 400 σελίδες
...(111.15) but L ABP is < a right / ; ANGLES IN CIRCLES. PROPOSITION XVII. 119 If a straight line touches a circle, and from the point of contact a straight line be drawn cutting the circle; the angles which this straight line makes with the tangent shall be equal h the angles in the alternate... | |
| Bombay city, univ - 1874 - 648 σελίδες
...meeting in F the lino CF which bisects the angle between CD and BC produced : prove that AE = EF. 3. If a straight line touch a circle and from the point of 8 contact a straight line bo drawn cutting the circle, the angles which this line makes with the line... | |
| Education Department,London - 1876 - 1010 σελίδες
...figure formed by joining the extremities of these four lines taken in order will be a rectangle. 3. If a straight line touch a circle and from the point of contact a straight line be drawn meeting the circle, the angles which this line makes with the line touching the circle shall be equal... | |
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