 | Euclides - 1872 - 102 pages
...all circles touched by both lines lie in two lines at right angles to each other. PROPOSITION XIX. THEOREM. If a straight line touch a circle, and from the point of contact a straight line be draicn at right angles to the touching line, the centre of the circle must be in that line. Let... | |
 | Euclides, James Hamblin Smith - Geometry - 1872 - 376 pages
...circle are normals to the circle at the points where they meet the circumference. PROPOSITION XIX. THEOREM. 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 must be in that line. Let the... | |
 | Henry Major - Student teachers - 1873 - 588 pages
...straight line from, F is perpendicular to DE, but FC ; therefore FC is perpendicular to DE. XIX. — 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... | |
 | Euclides - 1874 - 342 pages
...the same two (I. 32) ; and when the adjacent angles are equal, they are right angles (I. Def. 10). PROPOSITION 32. — Theorem. If a straight line touch...circle ; and from the point of contact a straight line be drawn meeting the circle; the angles which this line makes with the line touching the circle shall... | |
 | Edward Atkins - 1874 - 428 pages
...perpendicular to DE, but FC; therefore FC is perpendicular to DE. PROPOSITIONS. Proposition 19.— Theorem. 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... | |
 | Braithwaite Arnett - 1874 - 130 pages
...double of the square on half the line, and of the square on the line between the points of section. 4. 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. Describe... | |
 | Bombay city, univ - 1874 - 648 pages
...meeting in F the lino CF which bisects the angle between CD and BC produced : prove that AE = EF. 3. If a straight line touch a circle and from the point of 8 contact a straight line bo drawn cutting the circle, the angles which this line makes with the line... | |
 | Robert Potts - Geometry - 1876 - 446 pages
...FC, that is, FC is perpendicular 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 ba drawn at right angles to the touching line, the center of the circle ihali be in that line. Let... | |
 | Education Department,London - 1876 - 1010 pages
...semicircle is a right angle. Construct a square equal to the difference of two given squares. • 2. If a straight line touch a circle and from the point of contact a straight line be drawn cutting the circle, the angle which mis line makes with the line touching the circle shall... | |
 | Edward Atkins - 1876 - 130 pages
...F(J is perpendicular to DE. Therefore, if a straight line, &o. QED, Proposition 19.— Theorem. Jf a straight line touch a circle, and from the point of contact a straight line be drawn at right angles to the touching liiie, the centre of the circle shall be in that line. Let... | |
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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. 
