A cylinder has a base diameter of 2 cm and a height of 4 cm. What is the lateral area of the cylinder in square centimeters?
一个圆柱的底面直径是2厘米，高4厘米，这个圆柱的侧面积是多少平方厘米．
<gadget id="calculator">3.14 * 2 * 4</gadget>
<output>25.12</output>

<result>25.12</result>