The radius of a circle is 5 cm, and the arc length subtended by a central angle is 6.28 cm. What is the central angle in degrees?
圆的半径为5厘米，一个圆心角所对的弧长为6.28厘米，这个圆心角多少度．
<gadget id="calculator">6.28 / 3.14 / 5</gadget>
<output>0.4</output>

<gadget id="calculator">0.4 * 180</gadget>
<output>72</output>

<result>72</result>