A parallelogram test field has a base of 120 meters and a height of 30 meters less than the base. What is its area in meters**2.
一块平行四边形试验田，底是120米，高比底少30米，它的面积是多少米**2．
<gadget id="calculator">120 - 30</gadget>
<output>90</output>

<gadget id="calculator">120 * 90</gadget>
<output>10_800</output>

<result>10_800</result>