The formula for the surface area of a cylinder is A=2πrh+2πr².
A=2πrh+2πr²
=2(3.14)(3)(4) + 2(3.14)(3)²
=6.28*3*4 + 6.28*9
=75.36+56.52
=131.88
The surface area of the cylinder is 131.88 in.²
As for the triangular prism, the formula is SA = wh + lw + lh + ls
w=width (2.7)
h=height (1.1)
l=length (4.2)
s=side
Since you don't know the side (which is the hypotenuse of the right triangle, use the Pythagorea formula a² + b² = c²
2.7² + 1.1² = c²(side)
7.29+1.21=8.5
The side is 8.5cm.
Now plug w, h, l, and s into SA = wh + lw + lh + ls
SA= (2.7*1.1)+(4.2*2.7)+(4.2*1.1)+(4.2*8.5)
SA= 2.97+11.34+4.62+35.7
SA=54.63
The surface area of the triangular prism is 54.63cm².
I hope I helped