If the diameter and height of the base of a cylinder are both 3 cm, what is the circumference of the base in cm?
一个圆柱体的底面直径和高都是3cm，它的底面周长是多少cm．
<gadget id="calculator">3.14 * 3</gadget>
<output>9.42</output>

<result>9.42</result>