A cylindrical oil tank with a bottom diameter of 4 meters and a height of 1.2 meters can hold how many liters of oil.
一个圆柱体的油箱，底面直径4米，高1.2米，可装油多少升．
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400 * 1.2 * 10</gadget>
<output>15_072</output>

<result>15_072</result>