The circumference of the bottom of a cylinder is 6.28 decimeters and the height is 5 decimeters. What is the area of the bottom of this cylinder dm**2.
一个圆柱底面周长是6.28分米，高是5分米，这个圆柱体的底面积是多少dm**2．
<gadget id="calculator">6.28 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<result>3.14</result>