174240
43560
1 acre = 43560 sq ft 16000 sq ft = 16000/43560 = 1600/4356 = 400/1089 = 0.3673 acres
5 x 43560/400 = 544.5ft
That would be 566,280 Acres.
100 ft * 400 feet = 40000 square feet = 40000/43560 = 0.92 acres, approx.
10890
Google "sqrt of 43560" ==>
188.5714
43560 X 0.2 = 8712
43560 feet is one acre.
12.1