A rectangle with a perimeter of 20 meters, if its length and width are increased by 5 meters, how much will its perimeter be increased by?
一个周长为20米的长方形，如果把它的长和宽都增加5米，那么它的周长增加多少米
<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<result>20</result>