Answer:
Question 3: 582 ft²
Question 4: 348 in²
Step-by-step Explanation:
Question 3:
Consider the solid shape given as being consisting of two rectangular prism. With careful examination, you'd observe that the offer one beneath has dimensions, 
The second one has 
Surface area of the bigger rectangular prism = total surface area - area of the surface that is joined to the smaller rectangular prism.
Area of the face joined to the smaller rectangular prism = 4*6 = 24 ft²
Surface area of the bigger rectangular prism = 


Surface area of the bigger rectangular prism = 438 ft²
Surface area of the smaller rectangular prism = total surface area of rectangular prism - area of the surface that is joined to the bigger rectangular prism.
= 


<em><u>Surface area of the solid = 438 + 144 = 582 ft²</u></em>
Question 4:
Surface area of the triangular prism is given as: 2(B.A) + P*L
Where,
B.A = area of 1 triangular base = ½*height of the triangle*base of the traingle
B.A = ½*6*16 = 3*16 = 48 in²
P = perimeter of 1 triangular base = sum of all sides of the triangle.
P = 16+10+10 = 36 in
L = length or height of prism =
Plug in the values to find surface area of the prism
Surface area = 2(B.A) + P*L
= 2(48) + 36*7 = 96 + 252 = 348 in²
<em><u>Surface area of prism = 348 in²</u></em>