Nine small squares of the same area can be used to form a large square. If the perimeter of each small square is 18 cm, what is the perimeter of the larger square in cm?
用9个面积相同的小正方形可拼成一个大正方形．如果每个小正方形的周长都是18厘米，那么大正方形的周长是多少厘米．
<gadget id="calculator">18 / 4</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">(9/2) * 3</gadget>
<output>27/2 = around 13.5</output>

<gadget id="calculator">(27/2) * 4</gadget>
<output>54</output>

<result>54</result>