Summer Clouds moderators
10/08/2017 at 15:50-
NP is tangent to circle center O at N,so \(NP\perp ON\) at N
Assume that the circle center O and the circle center P touch each other at M, then O,M,P are collinear.
=> OP = OM + MP = 16 + 4 = 20 (cm)
Applying the Pythagoras theorem to the right \(\Delta ONP\),we have :
\(NP=\sqrt{OP^2-ON^2}=\sqrt{20^2-16^2}=\sqrt{144}=12\left(cm\right)\)
So,the answer is 12 cm
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