A rectangular iron plate is 15 decimeters in length and 2/3 in width. Cut the largest circle on this iron plate. What is the area of this circle?
一块长方形铁板，长15分米，宽是长的(2/3)，在这块铁板上截一个最大的圆，这个圆的面积是多少？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">15 * (2/3)</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<result>78.5</result>