A tangent line to a circle is any line which intersects the circle in exactly one point. You can think of a tangent line as "just touching" the circle, without ever traveling "inside". A line which intersects a circle in two points is called a secant line. Chords of a circle will lie on secant lines.
The precise statement of the conjecture is:
Conjecture (Tangent Conjecture I ):
Any tangent line to a circle is perpendicular to the radius drawn to the point of tangency.
Conjecture (Tangent Conjecture II ):
Tangent segments to a circle from a point outside the circle are equal in length.
Interactive Sketch Pad Demonstration:
- Key Curriculum Press can provide demo versions of Geometer's Sketch Pad
- Linked Sketch Pad Demonstrations of the
Please feel free to try the activity sheet associated with this conjecture.
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