Use a 40 cm long rope to wrap around a square frame exactly, what is the side length of the frame in cm?
用一根长40厘米的绳子正好绕一个正方形镜框的一周，这个镜框边长是多少厘米．
<gadget id="calculator">40 / 4</gadget>
<output>10</output>

<result>10</result>