A terraced field with an upper base of 36 meters, a lower base of 54 meters and a height of 40 meters. What is the area of the wheat field in square meters?
一块梯田，上底36米，下底54米，高40米．这块麦田的面积是多少平方米？
<gadget id="calculator">36 + 54</gadget>
<output>90</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">90 * 20</gadget>
<output>1_800</output>

<result>1_800</result>