Help with this circle geometry question? (1 Viewer)

[ertceps]

AB is the common chord of the circles and has been produced to P. From P, the tangents PT and PW have been drawn to the circles.
i) Prove WP = PT
ii) If BP = 14.6cm and PT = 19.4cm, find the length of AB

thank you!

 

[liquid_soda]

Can you post a diagram?

 

[ertceps]

http://m.imgur.com/9Bugh95

 

[Squar3root]

http://m.imgur.com/9Bugh95

that photo quality tho

 

[ertceps]

that photo quality tho

ocrap, didnt even notice

 

[FlyingGullible]

Try tangent-secant theorem.

 

[InteGrand]

AB is the common chord of the circles and has been produced to P. From P, the tangents PT and PW have been drawn to the circles.
i) Prove WP = PT
ii) If BP = 14.6cm and PT = 19.4cm, find the length of AB

thank you!

Call the left circle in the diagram , and the right circle .

i) Using the circle geometry theorem "square of tangent equals product of intercepts of intersecting secant" applied to , we have .

Using this same theorem applied to , we have .

It follows that .

ii) Again using this theorem applied to , we have .

 

[ertceps]

Call the left circle in the diagram , and the right circle .

i) Using the circle geometry theorem "square of tangent equals product of intercepts of intersecting secant" applied to , we have .

Using this same theorem applied to , we have .

It follows that .

ii) Again using this theorem applied to , we have .

thanks man! really appreciate it