 | Peter Nicholson - Mathematics - 1825 - 1046 pages
...to DE. Therefore, if a straight line, &c. QED Proposition XIX. Tliearem. 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... | |
 | 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... | |
 | Euclides - 1834 - 518 pages
...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...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 the alternate... | |
 | 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...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 the alternate... | |
 | 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... | |
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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. 
