piece of rectangular glass is truncated by 5 decimeters in length and 3 decimeters in width, and the remaining part is a square. Given that the area cut off is 71 square decimeters, what is the area of the remaining square?
一块长方形玻璃，长截去5分米，宽截去3分米，剩下的部分是正方形．已知截去的面积是71平方分米，那么剩下的正方形的面积是多少平方分米．
<gadget id="calculator">7 * 7</gadget>
<output>49</output>

<result>49</result>