What is the surface area of the triangular prism shown? a. 860 ft 2 b. 920 ft 2 c. 1,040 ft 2 d. 760 ft 2

We know that
surface area=2*area of the base+perimeter of base*height 

area of the base=b*h/2
b=8 ft
h=15 ft
so
area of triangle=8*15/2> 60 ft²

perimeter of base=a+b+c
a=15 ft
b=8 ft
c=?
applying the Pythagoras theorem
c²=a²+b²> c²=15²+8²> c²=225+64> 289
c=√289> c=17 ft
perimeter=15+8+17=40 ft

height of the prism=20 ft

surface area=2*60+40*20> 920 ft²

the answer is the option
B. 920 ft 2

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.