How to draw a tangent line for a circle which come through a given point outside of the circle
44159
How can I draw a tangent ending smoothly in a circle?
140964
How to draw tangent vectors and component vectors on a curve
107812
Script access to tangent and bitangent, per face: how?
72729
How to draw arbitrary closed surface with TikZ?
153767
Singular points and tangent lines
119913
How do I find a point a given distance from another point along a line?
126033
Rotate a point on a circle with known radius and position
70598
Find a line along a circle's perimeter?
2597
Line between points in projective space?
81777
Sum of radii of intersecting circles internally tangent to another circle
76767
Can a line of π lengths be drawn with a compass and straight edge?
55124
Conformally Map Region between tangent circles to Disk
48477
Finding an equation of circle which passes through three points
61641
Equations of lines tangent to an ellipse
37448
Two Circles and Tangents from Their Centers Problem
46869
Define a coordinate on a circle
123426
Find the approximate center of a circle passing through more than three points