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.
(In reply to
re: Seriously by Charlie)
Indeed.
If we were to consider X to at an infinite distance from O (ie, / DPB approaches 0º) the / POX approaches 90º as the limit such that
/ YOP is almost a rightangle.
Yes, as / DPB widens the points X, D, E and Y converge at a point to the left (on my sketch) of this vertical location.
I tried this in ACAD using a few different angle sizes for / DPB. Back to a straightedge and pair of compasses.
Edited on March 15, 2008, 7:24 pm

Posted by brianjn
on 20080315 19:21:18 