A rope just forms a rectangle with a length of 5 decimeters and a width of 3 decimeters. If it forms a square, what is the length of its sides?
一条绳子正好围成一个长5分米，宽是3分米的长方形，如果围成一个正方形，它的边长应该是多少．
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<result>4</result>