What is the length of a semicircle with a radius of 2.4 cm.
半径为2.4厘米的半圆弧长为多少厘米．
<gadget id="calculator">2.4 / 2</gadget>
<output>1.2</output>

<gadget id="calculator">2 * 3.14 * 1.2</gadget>
<output>7.536</output>

<result>7.536</result>