| John Keill - Logarithms - 1723 - 444 pages
...in AC. For if it be not, let F be the Center, if poffible, and join CF. Then becaufe the Right Line DE touches the Circle ABC, and FC is drawn from the Center to the * 18 of this. Point of Contact ; FC will be perpendicular to DE*. And fo the Angle FCE is a Right one.... | |
| Euclid, John Keill - Geometry - 1733 - 444 pages
...in AC. For if it be not, let F be the Center, if poflible, and join CF. Then becaufe the Right Line DE touches the Circle ABC, and FC is drawn from the Center to the Point of Contact ; FC will be perpendicular to t^Wr-DE*. And fo the Angle FCE is a Right one. /i<But ACE is alfo a Right... | |
| Robert Simson - Trigonometry - 1762 - 488 pages
...center of the circle is iv CA. . .-. For if not, let F be the center, if poffible, and join CF. Becaufe DE touches the circle ABC,, and FC is drawn from the center to the point a. 18. j. of contact, FC is perpendicular * to DE ; therefore FCE is a right angle. but ACE is alfo... | |
| Robert Simson - Trigonometry - 1775 - 534 pages
...center of the circle is in CA. For, if not, let F be the center, if poflible, and join CF ; Becaufe DE touches the circle ABC, . and FC is drawn from the center to .•"• the point of contact, FC is perpena 18. 3. tlicular* to DE ; therefore FCE is a right angle : But ACE is alfo a right angle; therefore... | |
| Robert Simson - Trigonometry - 1804 - 530 pages
...the center of the circle is in CA. For if not, let F be the center, if poffible, and join CF. Becaufe DE touches the circle ABC, and FC is drawn from the...the point of contact, FC is perpendicular » to DE ; therefore FCE is a right angle. but ACE is alfo a right angle ; there- . fore the angle FCE is equal... | |
| John Playfair - Mathematics - 1806 - 320 pages
...right angles to DE ; the centre of the circle is in CA. For, if not, let F be the centre, if possible, and join CF. Because DE touches the circle ABC, and FC is drawn from the centre to the point of cona 18. 3. tact, FC is perpendicular* to DE ; therefore FCE is a right angle.... | |
| Robert Simson - Trigonometry - 1806 - 546 pages
...drawn at right angles to DE ; the centre of the circle is in CA. For, if not, let F be the centre, because DE touches the circle ABC, and FC is drawn from the centre to the point of contact, FC a 18. 3. is perpendicular » to DE ; therefore FCE is a right angle:... | |
| Euclides - 1814 - 560 pages
...right angles to DE; the centre of the circle is in CA. For, if not, let F be the centre, if possible, and join CF ; Because DE touches the circle ABC, and FC is drawn from the centre to the point of contact, • 18.3. FC is perpendicular a to DE 3 therefore FCE is a right angle... | |
| Euclides - 1816 - 588 pages
...right angles to DE ; the centre of the circle is in CA. For, if not, let F be the centre, if possible, and join CF; Because DE touches the circle ABC, and FC is drawn from the centre to the point of contact, M8.3. FC is perpendicular a toDE; therefore FCE is a right angle :... | |
| John Playfair - Circle-squaring - 1819 - 350 pages
...right angles to DE ; the centre of the circle is in CA. For, if not, let F be the centre, if possible, and join CF : Because DE touches the circle ABC, and FC is drawn from the centre to the point of contact, FC is perpendicular (13. 3.) to DE ; therefore FCE is a right angle... | |
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