The worker uncle dug a swimming pool. The cross-section of the pool is a trapezoid. The pool is 1.5 meters deep, the bottom of the pool is 3.2 meters wide, and the mouth of the pool is 4 meters wide. What is the cross-sectional area of the pool?
工人叔叔挖一个游泳池，泳池的横截面是一个梯形，这个泳池深1.5米，池底宽3.2米，池口宽4米，这个泳池的横截面的面积是多少？
<gadget id="calculator">4 + 3.2</gadget>
<output>7.2</output>

<gadget id="calculator">1.5 / 2</gadget>
<output>0.75</output>

<gadget id="calculator">7.2 * 0.75</gadget>
<output>5.4</output>

<result>5.4</result>