| 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... | |
| |