Answer:
B. 120 m²
Step-by-step explanation:
To find the surface area of the composite solid, we would need to calculate the area of each solid (square pyramid and square prism), then subtract the areas of the sides that are not included as surface area. The sides not included as surface area is the side the pyramid and the prism is joint together.
Step 1: find the surface area of the pyramid:
Surface area of pyramid with equal base sides = Base Area (B) + ½ × Perimeter (P) × Slant height (l)
Base area = 4² = 16 m
Perimeter = 4(4) = 16 m
Slant height = 3 m
Total surface area of pyramid = 16 + ½ × 16 × 3
= 16 + 8 × 3 = 16 + 24
= 40 m²
Step 2: find the area of the prism
Area = 2(wl + hl + hw)
Area = 2[(4*4) + (5*4) + (5*4)]
Area = 2[16 + 20 + 20]
Area of prism = 2[56] = 112 m²
Step 3: Find the area of the sides not included
Area of the sides not included = 2 × area of the square base where both solids are joint
Area = 2 × (4²)
Area excluded = 2(16) = 32 m²
Step 4: find the surface area of the composite shape
Surface area of the composite shape = (area of pyramid + area of prism) - excluded areas
= (40m²+112m²) - 32m²
= 152 - 32
Surface area of composite solid = 120 m²
