Problem
Given the circle below with secant \( \overline{P O N} \) and tangent \( \overline{M N} \), find the length of \( \overline{P O} \). Round to the nearest tenth if necessary.
Solution
Step 1 ：Step 1: Apply the secant-tangent theorem: \(M N^2 = P N \cdot P O\).
Step 2 ：Step 2: Plug in given values: \(12^2 = 20 \cdot P O\).
Step 3 ：Step 3: Solve for \(P O\): \(P O = \frac{144}{20} = 7.2\)
