If the length of a rectangle is 40 cm and the width is 50% shorter than the length, what is the perimeter of the rectangle in cm?
一个长方形的长是40厘米，宽比长短50%，这个长方形的周长是多少厘米．
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 * (1/2)</gadget>
<output>20</output>

<gadget id="calculator">40 + 20</gadget>
<output>60</output>

<gadget id="calculator">60 * 2</gadget>
<output>120</output>

<result>120</result>