A cylinder has a base circumference of 31.4 cm and a height of 20 cm, what is its lateral area in square centimeters?
一个圆柱体的底面周长是31.4厘米，高20厘米，它的侧面积是多少平方厘米．
<gadget id="calculator">31.4 * 20</gadget>
<output>628</output>

<result>628</result>