The area of a sector is (2/3) of the area of the circle on which it is located. What is the central angle of the sector?
一扇形面积是所在圆面积的(2/3)，扇形的圆心角是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">360 * (2/3)</gadget>
<output>240</output>

<result>240</result>