The lines PC and PB are the secant and the tangent lines of the circle, while the proportion involving PA, PB, and PC is PA * PC = PB²
Why the triangles are similar triangles?
The triangles are given as:
Δ PAB and Δ PBC
Both triangles have a common point at P.
This means that:
∠P ≅ ∠P --- reflexive property of congruent angles
Also, the angles at C and B are congruent:
This is represented as:
∠B ≅ ∠C
Both triangles have a common side length PB.
Hence, the triangles are similar by ASA similarity theorem
The proportion involving PA, PB, and PC
The similarity theorem in (a) is the ASA similarity theorem.
This means that:
PA : PB = PB : PC
Express as fraction
[tex]\frac{PA}{PB} = \frac{PB}{PC}[/tex]
Cross multiply the expressions
PA * PC = PB * PB
Evaluate the product
PA * PC = PB²
Hence, the proportion involving PA, PB, and PC is PA * PC = PB²
Read more about secant and tangent lines at:
https://brainly.com/question/14962681
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