Books Books
... the centre of the circle shall be in that line. Let the straight line DE touch the circle ABC in C, and from C let CA be drawn at right angles to DE ; the centre of the circle is in CA.
The Elements of Euclid: With Many Additional Propositions, & Explanatory ... - Page 89
by Euclid - 1853 - 136 pages

## Euclid's Elements of Geometry: From the Latin Translation of Commandine. To ...

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's Elements of Geometry,: From the Latin Translation of Commandine. To ...

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...

## The Elements of Euclid: The Errors, by which Theon, Or Others, Have Long Ago ...

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...

## The Elements of Euclid, Viz: The Errors, by which Theon, Or Others, Have ...

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...

## The Elements of Euclid: Also the Book of Euclid's Data ...cor. viz. The ...

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...

## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

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....

## The Elements of Euclid: The Errors, by which Theon, Or Others, Have Long Ago ...

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:...

## The Elements of Euclid; viz. the first six books, together with the eleventh ...

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...