A cylinder has a base diameter of 6 cm and a height of 20 cm. What is the lateral area of the cylinder?
一个圆柱体底面直径是6厘米，高20厘米，这个圆柱的侧面积是多少．
<gadget id="calculator">3.14 * 6 * 20</gadget>
<output>376.8</output>

<result>376.8</result>