What’s the surface area of the triangular prism

Answer:
405.57551
Step-by-step explanation:
A=2AB+(a+b+c)h
AB=s(s﹣a)(s﹣b)(s﹣c)
s=a+b+c
2
Solving forA
A=ah+bh+ch+1
2﹣a4+2(ab)2+2(ac)2﹣b4+2(bc)2﹣c4=12·8+10·8+14·8+1
2·﹣124+2·(12·10)2+2·(12·14)2﹣104+2·(10·14)2﹣144≈405.57551