The diameter of the base is 2.5 cm and the height is 5 cm. Find the lateral area of the cylinder.
底面直径是2.5厘米，高是5厘米．求圆柱的侧面积．
<gadget id="calculator">3.14 * 2.5 * 5</gadget>
<output>39.25</output>

<result>39.25</result>