there are 43560 SF in an acre first you want to find the total SF witch is 43560x25=1089000 SF. also the common area will take up about 35% of the overall area so do .35x1089000=381,150 and subtract that from the overall SF witch gives you 707,850 then divide this by 25000 SF for the total number of lots that the developer can have on this property witch is 28 or 28.3 rounded to the tenths.
