Line at Right Angles to Diameter of Circle/Porism

From ProofWiki
Jump to navigation Jump to search

Theorem

In the words of Euclid:

From this it is manifest that the straight line drawn at right angles to the diameter of a circle from its extremity touches the circle.

(The Elements: Book $\text{III}$: Proposition $16$ : Porism)


Proof

Follows directly from Line at Right Angles to Diameter of Circle.


Sources