It is known that in the parallelogram ABCD, BC=3 cm, and the height AE on the side of BC is 2 cm, what is the area of triangle ACD in square centimeters?
已知平行四边形ABCD中，BC=3厘米，BC边上的高AE是2厘米，则三角形ACD的面积是多少平方厘米．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">3 * 1</gadget>
<output>3</output>

<result>3</result>