If the perimeter of a rectangle is 40 cm and the width is 3/5 of the length, what is the area of the rectangle in square centimeters?
一个长方形的周长是40厘米，宽是长的(3/5)，则长方形的面积是多少平方厘米．
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">20 * (5/8)</gadget>
<output>25/2 = around 12.5</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">20 * (3/8)</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">(25/2) * (15/2)</gadget>
<output>375/4 = around 93.75</output>

<result>375/4 = around 93.75</result>