A rectangle with a perimeter of 60 cm is composed of 3 identical small squares. What is the perimeter of each small square in centimeters?
一个长方形，周长是60厘米，它是由3个完全相同的小正方形拼成的．那么每个小正方形的周长是多少厘米．
<gadget id="calculator">60 / 8</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">(15/2) * 4</gadget>
<output>30</output>

<result>30</result>