What is the circumference of a semicircle with a diameter of 2 cm.
一个直径为2厘米的半圆面，它的周长是多少厘米．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<gadget id="calculator">3.14 + 2</gadget>
<output>5.14</output>

<result>5.14</result>