The diameter of a circular pond is 10 meters. A circular path with a width of 2 meters is built around the pond. What is the area of the path?
一个圆形池塘的直径是10米，在池塘的周围修一条2米宽的环形小路，这条小路的面积是多少？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">7 ** 2</gadget>
<output>49</output>

<gadget id="calculator">3.14 * 49</gadget>
<output>153.86</output>

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

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

<gadget id="calculator">153.86 - 78.5</gadget>
<output>75.36</output>

<result>75.36</result>