Solve the problem title: The area of a circle after shrinking is the original (1/81), and the radius before shrinking is 45 cm. What is the reduced circumference?
解决问题题目：-个圆缩小后面积是原来的(1/81)，缩小前半径是45厘米．缩小后的周长是多少？
<gadget id="calculator">45 / 9</gadget>
<output>5</output>

<gadget id="calculator">2 * 3.14 * 5</gadget>
<output>31.4</output>

<result>31.4</result>