Draw the largest semicircle in a rectangle with a length of 5 cm and a width of 2 cm. What is the circumference of this semicircle in cm?
在长5厘米、宽2厘米的长方形中画一个最大的半圆，这个半圆的周长是多少厘米．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">3.14 * 2</gadget>
<output>6.28</output>

<gadget id="calculator">6.28 + 4</gadget>
<output>10.28</output>

<result>10.28</result>