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.

Assuming circle and P are in same plane, draw the line connecting O and P, and draw a line perpendicular to that line where the line intersects the circle (touches circle at one point only) -- but surely you don't mean that (what does "straightedge only" allow)?

Posted by ed bottemiller on 2008-03-13 11:46:24