The circumference of a cylindrical base is 31.4 cm and the height is 10 cm. What is its lateral area?
一个圆柱底面周长是31.4厘米，高是10厘米，它的侧面积是多少．
<gadget id="calculator">31.4 * 10</gadget>
<output>314</output>

<result>314</result>