All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Shapes > Geometry
Tangent with Straightedge (Posted on 2008-03-13) Difficulty: 4 of 5
Let gamma be a circle with center O and P a point outside gamma.

Construct a tangent line to gamma through point P using a straightedge only.

Prove the construction.

See The Solution Submitted by Bractals    
Rating: 4.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: Seriously | Comment 6 of 8 |
(In reply to Seriously by brianjn)

It is indeed true that "as / DPB widens, D, E and X approach each other, seemingly at point Y which is the apparent tangent intersection," but during that movement, Y also changes position.  Y only approaches the tangent point as D and E also approach it. So in the general, secant, case, Y is not the point of tangency.

(I tried this out on Geometers Sketchpad; Y does move.)

  Posted by Charlie on 2008-03-15 10:11:24

Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (1)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2019 by Animus Pactum Consulting. All rights reserved. Privacy Information