A square card is surrounded by a ribbon with a length of 29 cm, and there is 1 cm longer than that. What is the side length of the square in cm?
用一条长29厘米的彩带把一张正方形卡片围一周，还长出1厘米，这个正方形的边长是多少厘米？
<gadget id="calculator">29 - 1</gadget>
<output>28</output>

<gadget id="calculator">28 / 4</gadget>
<output>7</output>

<result>7</result>