trapezoidal flower platform, the upper base is 12 meters long, the lower base is 18 meters long, and the height is 10 meters. How many square meters does this flower bed occupy?
一个梯形花台，上底长12米，下底长18米，高10米．这个花台的占地面积是多少平方米？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">30 * 5</gadget>
<output>150</output>

<result>150</result>