Discussion

If the area of circle is 616 sq cm then its circumference?

Answer: B

Find the radius from the area, then use it for the circumference.

\[ \pi r^{2} = 616 \quad\Longrightarrow\quad r^{2} = \frac{616 \times 7}{22} = 196 \]

\[ r = 14 \text{ cm} \]

\[ C = 2\pi r = 2 \times \frac{22}{7} \times 14 = 88 \text{ cm} \]

The two formulas share \( \pi \) but not the power of \( r \), so the radius must be extracted before the circumference can be found.

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