The radius of the base of a cylinder is 1 cm and the height is 2.5 cm, what is its lateral area in square centimeters?
一个圆柱底面半径是1厘米，高是2.5厘米，它的侧面积是多少平方厘米．
<gadget id="calculator">3.14 * 1 * 2 * 2.5</gadget>
<output>15.7</output>

<result>15.7</result>