A wall clock (radius 18 cm) has a chord forming equilateral triangle with two radii at center. Smaller segment painted. What percentage of total area(approximate)?

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1. The two radii and the chord form an equilateral triangle, so the central angle is $60^\circ$.

2. Sector area = $\frac{60}{360}\pi R^2=\frac{1}{6}\pi(18)^2=54\pi$.

3. Triangle area = $\frac{\sqrt3}{4}	imes18^2=81\sqrt3$.

4. Small segment area = sector − triangle = $54\pi-81\sqrt3\approx29.25$.

5. Circle area = $\pi(18)^2=324\pi\approx1017.88$. Percent = $\frac{29.25}{1017.88}	imes100\approx2.87\%\approx3\%$.

FINAL_ANSWER: b

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