A square with side length 4 cm and a rectangle with length 5 cm and width 3 cm. What is their circumference.
一个边长是4厘米的正方形和一个长5厘米、宽3厘米的长方形．它们的周长都是多少．
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

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

<result>16</result>