Use 72cm long ribbons to form a rectangle. The ratio of the length to width of the rectangle is 4:5. What is the area of the rectangle in square centimeters?
用72cm长的彩带围成一个长方形，长方形的长和宽的比是4：5，长方形的面积是多少平方厘米．
<gadget id="calculator">72 / 2</gadget>
<output>36</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">36 * (4/9)</gadget>
<output>16</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">36 * (5/9)</gadget>
<output>20</output>

<gadget id="calculator">16 * 20</gadget>
<output>320</output>

<result>320</result>