The perimeter of a rectangle is 28cm, and the ratio of length to width is 5:2. Draw the largest circle inside this rectangle. What is the area of the circle in square centimeters?
一个长方形的周长是28cm，长与宽的比是5：2，在这个长方形里面画一个最大的圆，圆的面积是多少平方厘米．
<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">14 * (2/7)</gadget>
<output>4</output>

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

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

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>