If a straight line touch a circle, and from the point of contact a chord be drawn, the angles which this chord makes with the tangent are equal to the angles in the alternate segments. Books 3-9 - Page 65by Euclid, Sir Thomas Little Heath, Johan Ludvig Heiberg - 1908Full view - About this book
| John Playfair - Trigonometry - 1806 - 311 pages
...one angle of a triangle be equal to the other two angles, it is a right angle. PROP. XXXII. THEOR. **IF a straight line touch 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 which touches... | |
| Euclid, Robert Simson - Geometry - 1810 - 518 pages
...FC is perpendicular to DE. Therefore, if a straight line, &c. QED C GE a 18. 3. ,' PROP. 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 lirie, the centre of the circle shall be in... | |
| Charles Butler - Mathematics - 1814
...demonstration, that these three perpendiculars BE, GF, and CD intersect each other in the same point AQED 249. **If a straight line touch a circle, and from the point of contact** two chords be drawn, and if from the extremity of one of them, a straight line be drawn parallel to... | |
| John Playfair - Trigonometry - 1819 - 333 pages
...DE ; FC is therefore perpendicular to DE. Therefore, if a straight line, &c. Q, ED PROP. 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, is in that... | |
| Robert Simson - Trigonometry - 1827 - 513 pages
...the same two ; and when the adjacent angles are equal, they are f right angles. PROP. XXXII. THEOR. **If a straight line touch a circle, and from the point of contact** a straight line be drawn cutting the circle ; the angles which this line makes with the line touching... | |
| Francis Nichols - Mathematics - 1829 - 186 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. •... | |
| Jeremiah Day - Mathematics - 1836 - 472 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 of contact** a straight line be drawn cutting the circle, the angles made by this line with the line which touches... | |
| John Playfair - Trigonometry - 1836 - 114 pages
...less than a right angle ; wherefore the other ADC is greater than a right angle. PROP. XXIII. THEOR. **If a straight line touch 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... | |
| Euclid - 1837 - 390 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... | |
| Euclides - 1838
...supposed to have been subjoined, not by Euclid, but by some one of the early editors. PROP. 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... | |
| |