A conical coal pile with a bottom circumference of 12.56 meters and a height of 3 meters. If each cubic meter of coal weighs 1.4 tons, how many tons does this pile of coal weigh?
一个圆锥形煤堆，底面周长12.56米，高3米．如果每立方煤重1.4吨，这堆煤重多少吨？
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3.14 * 4 * 3 * (1/3) * 1.4</gadget>
<output>17.584</output>

<result>17.584</result>