circular aquarium has a circumference of 251.2 meters. Now it is necessary to widen its circumference by 1 meter. How many square meters will the area increase after the widening?
一个圆形养鱼池，周长为251.2米，现在要在它的周围加宽1米，加宽后的面积比原来增加了多少平方米？
<gadget id="calculator">251.2 / 3.14 / 2</gadget>
<output>40</output>

<gadget id="calculator">40 + 1</gadget>
<output>41</output>

<gadget id="calculator">41 ** 2</gadget>
<output>1_681</output>

<gadget id="calculator">3.14 * 1_681</gadget>
<output>5_278.34</output>

<gadget id="calculator">40 ** 2</gadget>
<output>1_600</output>

<gadget id="calculator">3.14 * 1_600</gadget>
<output>5_024</output>

<gadget id="calculator">5_278.34 - 5_024</gadget>
<output>254.34</output>

<result>254.34</result>