A rectangle is 8 cm long and 4.56 cm wide. What is the area of a circle equal to the perimeter of the rectangle?
一个长方形的长8厘米，宽4.56厘米，与这个长方形周长相等的圆的面积是多少？
<gadget id="calculator">8 + 4.56</gadget>
<output>12.56</output>

<gadget id="calculator">2 * 12.56</gadget>
<output>25.12</output>

<gadget id="calculator">25.12 / 3.14 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<result>50.24</result>