A rectangular playground with a length of 80m and a width of 60m is enlarged by 20m in both length and width. Find the area of the playground after expansion.
一块长80m，宽60m的长方形操场，经过扩建后，长宽各增加了20m，求扩建后操场的面积．
<gadget id="calculator">80 + 20</gadget>
<output>100</output>

<gadget id="calculator">60 + 20</gadget>
<output>80</output>

<gadget id="calculator">100 * 80</gadget>
<output>8_000</output>

<result>8_000</result>