Grandpa ran 10 laps around a circular pool and ran a total of 314m. How many square meters does this circular pool occupy?
爷爷围着一个圆形水池跑10圈，一共跑了314m，那么这个圆形水池的占地面积是多少平方米？
<gadget id="calculator">314 / 10 / 3.14 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<result>78.5</result>