Dad asked Xiaoqiang to use a piece of wire to form a rectangle with a length of 8 decimeters and a width of 4 decimeters. As a result, Xiaoqiang formed a square. Please help Xiaoqiang to calculate. What is the side length of this square?
爸爸叫小强用一条铁丝围成一个长8分米，宽4分米的长方形，结果小强围成一个正方形，请你帮小强算一算，这个正方形的边长是多少分米？
<gadget id="calculator">8 + 4</gadget>
<output>12</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">12 * (1/2)</gadget>
<output>6</output>

<result>6</result>