As shown in the figure, a middle school has a rectangular site with a length of AM and a width of BM. It is planned to build two mutually perpendicular roads with a width of 2m on the site, and the remaining 4 roads will be built

As shown in the figure, a middle school has a rectangular site with a length of AM and a width of BM. It is planned to build two mutually perpendicular roads with a width of 2m on the site, and the remaining 4 roads will be built

1. The area of each road is 2am ^ 2 and 2bm ^ 2.2 respectively. From the topic meaning, (A-2) (b-2) = 312, because a: B = 2:1, so a = 2B. Then (2b-2) (b-2) = 312, the solution is: B = 14, B = - 11 (rounding off), so a = 28. The length of the original rectangular field is 28m, and the width is 14m