There is a piece of wood with a side length of 4 decimeters. If this piece of wood is processed into a largest cylinder, what is the area of the bottom of this cylinder dm**2.
有一块正方体的木料，它的棱长是4分米，把这块木料加工成一个最大的圆柱体，这个圆柱的底面积是多少dm**2．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>