The perimeter of a rectangle is 30 centimeters, and the width is 2/3 the length. What is the area of this rectangle in square centimetres.
一个长方形的周长是30厘米，宽是长的(2/3)．这个长方形的面积是多少平方厘米．
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">15 * (3/5)</gadget>
<output>9</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">15 * (2/5)</gadget>
<output>6</output>

<gadget id="calculator">9 * 6</gadget>
<output>54</output>

<result>54</result>