The area of quadrilateral ABCD is 36 square centimeters, AD=CD, AP=3cm, find the area of quadrilateral APCD.
四边形ABCD的面积是36平方厘米，AD=CD，AP=3cm，求四边形APCD的面积．
<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">36 - 9</gadget>
<output>27</output>

<result>27</result>