The side view of a cylinder is a square. It is known that the circumference of its base is 31.4 cm. What is its volume?
一个圆柱的侧面展开图是正方形，已知它的底面周长是31.4厘米，它的体积是多少．
<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

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

<gadget id="calculator">3.14 * 25 * 31.4</gadget>
<output>2_464.9</output>

<result>2_464.9</result>