Given that the arc length of the sector is 31.4 meters and the radius is 10 meters, what is the area of the sector in square meters?
已知扇形的弧长是31.4米，半径是10米，那么扇形的面积是多少平方米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 31.4 * 10</gadget>
<output>157</output>

<result>157</result>