Difference between revisions of "Two Tangent Theorem"

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The two tangent theorem states that given a circle, if P is any point lying outside the circle, and if A and B are points such that PA and PB are tangent to the circle, then PA = PB.
 
The two tangent theorem states that given a circle, if P is any point lying outside the circle, and if A and B are points such that PA and PB are tangent to the circle, then PA = PB.
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<geogebra>4f007f927909b27106388aa6339add09df6868c6</geogebra>
  
It follows from [[Power of a Point]] trivially, or we can use similar triangles, given that tangents to a circle form a right angle to the radius to the point of tangency.
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== Proofs ==
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=== Proof 1 ===
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Since <math>OBP</math> and <math>OAP</math> are both right triangles with two equal sides, the third sides are both equal.
  
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=== Proof 2 ===
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From a simple application of the [[Power of a Point Theorem]], the result follows.
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==See Also==
 
{{stub}}
 
{{stub}}
 
 
[[Category:Geometry]]
 
[[Category:Geometry]]
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[[Category: Theorems]]

Latest revision as of 21:47, 5 December 2023

The two tangent theorem states that given a circle, if P is any point lying outside the circle, and if A and B are points such that PA and PB are tangent to the circle, then PA = PB. <geogebra>4f007f927909b27106388aa6339add09df6868c6</geogebra>

Proofs

Proof 1

Since $OBP$ and $OAP$ are both right triangles with two equal sides, the third sides are both equal.

Proof 2

From a simple application of the Power of a Point Theorem, the result follows.

See Also

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