If the length of an arc accounts for (5/18) of the circumference of the circle it is on, what is the central angle subtended by this arc?
有一段弧的长度占它所在圆周长的(5/18)，那么这段弧所对的圆心角是多少度．
<gadget id="calculator">5 / 18</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">360 * (5/18)</gadget>
<output>100</output>

<result>100</result>