Books Books 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 be equal to the angles which are in the alternate segments of the... Euclid in Paragraphs: The Elements of Euclid: Containing the First Six Books ... - Page 69
by Euclid - 1845 - 199 pages ## Pantologia. A new (cabinet) cyclopædia, by J.M. Good, O. Gregory ..., Volume 5

John Mason Good - 1819 - 740 pages
...less than a semicircle is greater than a right angle. Prop. XXX IL Thcor. If a straight line touche» a circle, and from the point of contact a straight line be drawn culling the circle, the angles made by this line with the line touching the circle, shall be equal... ## A Popular Course of Pure and Mixed Mathematics ...: With Tables of ...

Peter Nicholson - Mathematics - 1825 - 1046 pages
...adjacent angles are equal, they are right angles. Proportion XXX IL Theorem. If a straight line touches 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 be equal... ## Elements of Geometry, Containing the First Six Books of Euclid

Euclid - 1826 - 236 pages
...line EF touches the circle ABCD, in the point в, and from the point of contact в a right line BA is drawn at right angles to the touching line, the centre of the circle ABCD will be in • 19. 3. BA.a Wherefore BA is a diameter of the same circle, and ADB an angle in... ## Euclid's Elements of geometry, transl. To which are added, algebraic ...

Euclides - 1826 - 226 pages
...line EF touches the circle ABCD, in the point в, and from the point of contact в a right line BA is drawn at right angles to the touching line, the centre of the circle ABCD will be in « 19.3. BA. a Wherefore BA is a diameter of the same circle, and ADB an angle in a... ## The Elements of Euclid: The Errors by which Theon, Or Others, Have Long ...

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 the circle, shall be equal... ## Elements of Geometry: Being Chiefly a Selection from Playfair's Geometry

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... ## Geometry, Plane, Solid, and Spherical, in Six Books: To which is Added, in ...

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, the centre of the circle shall be in that line. Cor. 3. Tangents ТА, ТВ which are drawn to a circle from the same point T, are equal to one another.... ## Library of Useful Knowledge: Geometry plane, solid, and spherical [by Pierce ...

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, the centre of the circle shall be in that line. Cor. 3. Tangents ТА, ТВ which are drawn to a circle from the same point T, are equal to one another.... ## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

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... 