If the perimeter of a rectangle is 42 cm and its width is 25% less than its length, what is the area of the rectangle in square centimeters?
一个长方形的周长是42厘米，它的宽比长少25%，这个长方形的面积是多少平方厘米．
<gadget id="calculator">42 / 2</gadget>
<output>21</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 + (3/4)</gadget>
<output>7/4 = around 1.75</output>

<gadget id="calculator">21 / (7/4)</gadget>
<output>12</output>

<gadget id="calculator">21 - 12</gadget>
<output>9</output>

<gadget id="calculator">12 * 9</gadget>
<output>108</output>

<result>108</result>