| Robert Simson - Trigonometry - 1827 - 546 pages
...perpendicular to I>E. Therefore, if a straight line, &c. QED PROP. XIX. THEOR. If a straight line taucJ1es 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... | |
| John Playfair - Geometry - 1829 - 210 pages
...to DE; therefore FC is perp. to DE. Therefore, if a straight line &c. QED PROPOSITION XIX. THEOREM. If a straight line touch a circle, and from the point of contact a straight line be drawn perpendicular to the tangent, the centre of the circle is in that line. • ' N CG 1) c E Let the straight... | |
| Pierce Morton - Geometry - 1830 - 584 pages
...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... | |
| John Playfair - Euclid's Elements - 1835 - 336 pages
...to the same two ; and when the adjacent angles are equal, they are right angles. PROP. XXX. THEOR. If a straight line touch a circle, and from the point of contact a straight line be draion cutting the circle, the angles made by this line with the line which touches the circle, shall... | |
| Mathematics - 1835 - 684 pages
...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... | |
| Mathematics - 1836 - 488 pages
...it 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...contact a straight line be drawn cutting the circle, the angles made by this line with the line which touches the circle, shall be equal to the angles in... | |
| John Playfair - Geometry - 1836 - 148 pages
...FC, 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 - Geometry - 1837 - 410 pages
...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 - Euclid's Elements - 1837 - 332 pages
...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 - 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... | |
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