Two parallel chords measuring 20 cm and 14 cm exist on the same side of center. The distance between them is 3 cm. What is the radius?

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1. Let the distances from center to the 20 cm and 14 cm chords be $d$ and $d+3$. The 20 cm chord is closer, so use $d$ for it.
2. Use the chord relation: $(\frac{L}{2})^2+d^2=R^2$. So $100+d^2=R^2$ and $49+(d+3)^2=R^2$.
3. Equate: $100+d^2=49+d^2+6d+9$. This gives $6d=42$, so $d=7$.
4. Then $R^2=100+7^2=149$. So $R=\sqrt{149}$.
FINAL_ANSWER: c

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