An illustration showing a quadrilateral inscribed in a circle that is tangent to a line.

An illustration showing a triangle with angles A, C, and D inscribed in a circle which is tangent to…

Illustration showing that tangents drawn at the ends of any diameter are parallel to each other.

Illustration of how to draw a tangent to an ellipse from an external point.

Diagram an ellipse with a tangent line that illustrates "A line through a point on the ellipse and bisecting…

Illustration showing the tangents drawn at two corresponding points of an ellipse and its auxiliary…

Diagram part of a hyperbola with a tangent line that illustrates "A line through a point on the hyperbola…