If the perimeter of a square is 28 decimeters, what is the length of its side in centimeters?
一个正方形的周长是28分米，它的边长是多少厘米．
<gadget id="calculator">28 * 10</gadget>
<output>280</output>

<gadget id="calculator">280 / 4</gadget>
<output>70</output>

<result>70</result>