After cutting a circle into an approximate rectangle, the circumference of this rectangle is measured to be 12.42 cm, so what is the original area in square centimeters?
把一个圆剪拼成一个近似的长方形后，量得这个长方形的周长为12.42厘米，那么原来的面积是多少平方厘米？
<gadget id="calculator">1.5 ** 2</gadget>
<output>2.25</output>

<gadget id="calculator">3.14 * 2.25</gadget>
<output>7.065</output>

<result>7.065</result>