Do your homework by yourself. This is the limit function problem in high school. Your question is also wrong, it should be how many meters Xiaoling runs at least!

The idea is: let length x width Y XY = 3000；; Find the maximum value of Z=2(X+Y)!

That is, (x+y) (x+y) = xx+2xy+YY = xx+YY+6000 = ZZ/4.

(X-Y)(X-Y)=XX-YY=NN

2XX+6000=ZZ/4+NN

2YY+6000=ZZ/4-NN

Where xx < 3000 YY <; 3000

ZZ/4+NN & gt； 12000

ZZ/4-NN & gt； 12000

ZZ & gt24000*4== >ZZ & gt96000 == > The limit value of z can be found.

You can also draw a graph Y=3000/X when X=Y and X+Y is the minimum.

This time it's the square!