The radius of a sector is 4.5 cm, and the central angle is 80 degrees. What is the perimeter of the sector in cm?
一个扇形的半径是4.5厘米，圆心角是80度，这个扇形的周长是多少厘米．
<gadget id="calculator">80 * 3.14 * 4.5</gadget>
<output>1_130.4</output>

<gadget id="calculator">1_130.4 / 180</gadget>
<output>6.28</output>

<gadget id="calculator">2 * 4.5</gadget>
<output>9</output>

<gadget id="calculator">6.28 + 9</gadget>
<output>15.28</output>

<result>15.28</result>