When a square playground is expanded, the opposite sides of the playground are increased by 16 meters, so the area of the playground is increased by 800 square meters. How many square meters is the original playground area?
一个正方形操场，扩建时，操场的一组对边各增加了16米，这样操场的面积就增加了800平方米，原来操场的面积是多少平方米？
<gadget id="calculator">800 / 16</gadget>
<output>50</output>

<gadget id="calculator">50 * 50</gadget>
<output>2_500</output>

<result>2_500</result>