circular nursery is surrounded by a 64-meter-long fence, and 1.2 meters are used at the fence joints. What is the size of the nursery?
用64米长的篱笆围成一个圆形苗圃，篱笆接头处用去1.2米．苗圃的面积多少？
<gadget id="calculator">64 - 1.2</gadget>
<output>62.8</output>

<gadget id="calculator">62.8 / 3.14 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<result>314</result>