There is a cylindrical oil tank in Dongfeng Chemical Plant. The radius of the bottom surface measured from the inside is 4 meters, and the height is 20 meters. The oil tank is filled with oil. If each cubic meter of oil weighs 700 kilograms, how many kilograms does the oil weigh?
东风化工厂有一个圆柱形油罐，从里面量的底面半径是4米，高是20米．油罐内已注满石油．如果每立方米石油重700千克，这些石油重多少千克？
<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16 * 20 * 700</gadget>
<output>703_360</output>

<result>703_360</result>