Why is it somewhat difficult to distinguish early christian art from other art of that time period?

Because the christianity was developed in the Roman Empire. So, at first, ethe christian art was some how a greco-roman art. And in that time, in Europe was the most common art. So it was difficult to distinguish it from others.

Sorry for my bad english, I speak spanish.

perimeter = 2l +2w, divide total perimeter by 2 for total length of 1 side and 1 width

172/2 = 86 (  total for 1 side and 1 width)

86-24 = 62 (since length is 24 ft longer subtract 24 then divide by 2 for width)

62/2 = 31

width = 31 feet

length = 31 +24 = 55 feet

check: 31*2 = 62, 55*2 = 110,  110+62 = 172

answer; i believe the correct answer is in new york,in subway stations,public murals and night clubs;