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# P3 - Edexcel - Length of a tangent watch

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1. This question is from the 2003 jan paper . We are given the center of the circle and the radius. Center of the circle is (4,5) radius is 5.

A tangent to the circle, drawn from the point P(8, 17), touches the circle at T.
(c) Find, to 3 significant figures, the length of PT.

Thanks.
2. (Original post by Paxi)
This question is from the 2003 jan paper . We are given the center of the circle and the radius. Center of the circle is (4,5) radius is 5.

A tangent to the circle, drawn from the point P(8, 17), touches the circle at T.
(c) Find, to 3 significant figures, the length of PT.

Thanks.
Draw out a sketch showing the circle and P. Then draw on a right angled triangle with sides PT, CP, CT, where C is the centre of the circle. You can then use pythagoras to find the required length as the radius makes right angle with the tangent.
3. Thanks ... sounds awfully simple now

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