The length of an arc is 25.12, and the central angle subtended by it is 120°, what is the radius of the circle where the arc is located?
一条弧的长度为25.12，所对圆心角为120°，那么弧所在的圆的半径为多少．
<gadget id="calculator">180 * 25.12</gadget>
<output>4_521.6</output>

<gadget id="calculator">120 * 3.14</gadget>
<output>376.8</output>

<gadget id="calculator">4_521.6 / 376.8</gadget>
<output>12</output>

<result>12</result>