After increasing the two adjacent sides of a square by 3 cm, a new square is obtained. The area of the new square is 39 square centimeters larger than the original one. What is the area of the original square in square centimeters?
把一个正方形相邻的两条边都增加了3厘米后，又得到一个新的正方形．新正方形的面积比原来增加了39平方厘米，原来的正方形的面积是多少平方厘米？
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">39 - 9</gadget>
<output>30</output>

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

<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<result>25</result>