If a circle with a diameter of 4 cm is divided into two equal semicircles, what is the sum of the circumferences of the two semicircles?
把一个直径是4厘米的圆分成两个完全相等的半圆，这两个半圆的周长之和是多少厘米
<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>

<gadget id="calculator">10.28 * 2</gadget>
<output>20.56</output>

<result>20.56</result>