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Question
Find the length of the tangent from a point which is at a distance of 5cm from the centre of the circle of radius 3cm.
Solution
OA ⊥ AP (radius is perpendicular to tangent at the point of contact)
In right Δ OAP,
OP2 = OA2 + AP2
AP2 = 52 -32
= 25 - 9 = 16
AP = 4 cm
The length of the tangent is 4cm .
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