A wire can just enclose a square with a side length of 78.5 cm. If it is used to enclose a circle, what is the area of the circle in square meters?
一根铁丝刚好能围成一个边长78.5cm的正方形，如果用它围成一个圆，这个圆的面积是多少平方米？
<gadget id="calculator">4 / 3.14 / 2</gadget>
<output>0.636943</output>

<gadget id="calculator">78.5 * 0.636943</gadget>
<output>50.000025</output>

<gadget id="calculator">50.000025 ** 2</gadget>
<output>2_500.0025</output>

<gadget id="calculator">2_500.0025 / 10_000</gadget>
<output>0.25</output>

<gadget id="calculator">3.14 * 0.25</gadget>
<output>0.785</output>

<result>0.785</result>