A steel wire is 18.84 decimeters long, and it encloses the largest circle, what is its area?
一根钢丝长18.84分米，把它围成一个最大的圆，它的面积是多少？
<gadget id="calculator">18.84 / 3.14 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>