A round pancake is cut 8 knives on its outside to get an octagon. What is the sum of the interior angles of this octagon?
一张圆形大饼在它的外面切了8刀，得一个八边形，问这个八边形的内角和为多少．
<gadget id="calculator">8 - 2</gadget>
<output>6</output>

<gadget id="calculator">6 * 180</gadget>
<output>1_080</output>

<result>1_080</result>