 | John Playfair - Mathematics - 1806 - 320 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 - Geometry - 1810 - 554 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... | |
 | John Playfair - Circle-squaring - 1819 - 348 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 - 546 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... | |
 | 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. •... | |
 | John Playfair - Geometry - 1836 - 148 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... | |
 | 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 of contact a straight line be drawn cutting the circle, the angles made by this line with the line which touches... | |
 | 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... | |
 | Euclides - 1838 - 264 pages
...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... | |
 | Euclides - Geometry - 1841 - 378 pages
...two; and when the adjacent angles are equal, they are right* angles. ģiol>ef. 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... | |
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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. 
