The circumference of the base of the cylinder is 31.4 decimeters, and the height is 10 decimeters. What is its lateral area in square decimeters?
圆柱的底面周长是31.4分米，高是10分米，它的侧面积是多少平方分米．
<gadget id="calculator">31.4 * 10</gadget>
<output>314</output>

<result>314</result>