| John Playfair - Euclid's Elements - 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 the circle will... | |
| Euclid - 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 that line. Let... | |
| Charles Butler - 1814 - 568 pages
...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 - Euclid's Elements - 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 line. Let the straight... | |
| 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 the circle, shall... | |
| John Playfair - Geometry - 1829 - 186 pages
...be perp. 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... | |
| Robert Simson - Trigonometry - 1835 - 513 pages
...the adjacent angles are equal, they are right angles. PROP. XXXII. THEOR. If a straight line touches **a circle, and from the point of contact a straight line is drawn** cutting the circle, the angles made by this line with tlie line touching the circle, are equal to the... | |
| Euclid - 1835 - 540 pages
...DE. —^ Therefore, " if a straight line," JJ &c. QED PROP. XIX. THEOR. GE If a straight line touches **a circle, and from the point of contact a straight line is drawn** at right angles to the touching line, the centre of the circle is in that line. Let the straight line... | |
| 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 the circle, shall... | |
| John Playfair - Geometry - 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 circle, shall... | |
| |