A. {9,10,11,12} 9 and 10 are elements of set A but 11 and 12 aren't elements of A. Subsets of A { } {1} {2} {3} {4} {5} {6} {7 } {8} { 9} {10} {1,2} {1,3} {1,4} {1,5} {1,6} {1,7} {1,8} {1,9} {1,10} {1,2,3} {1,2,4} {1,2,5}........ you can write like this using all the elements of A
since the smallest possible prime number is 2 it would make since if each side is 2 which makes the smallest perimeter possible. i really hope this helped :)
