The radius of a semicircle is 5 cm, what is the circumference of the semicircle in cm
半圆的半径是5cm，半圆的周长是多少cm
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">2 * 3.14 * (5/2)</gadget>
<output>15.7</output>

<gadget id="calculator">2 * 5</gadget>
<output>10</output>

<gadget id="calculator">15.7 + 10</gadget>
<output>25.7</output>

<result>25.7</result>