Use the image to answer the question.

An illustration shows a 3-dimensional line diagram of a truck that appears as two adjoining rectangular prisms placed on two visible wheels. The rectangular prism on the left, representing the cab section of the truck, has a length of 4 feet and a height of 4 feet. The rectangular prism on the right, representing the cargo section, has a length of 15 feet and a height of 7.5 feet. The back of the truck is marked with a depth of 7.5 feet.

A truck’s cargo bed has the dimensions shown. What is the approximate total surface area of the truck and its bed? Round the answer to the nearest tenth.

(1 point)
Responses

684.5 ft.2
684.5 ft. squared

654.5 ft.2
654.5 ft. squared

714.5 ft.2
714.5 ft. squared

1,927.5 ft.2

1 answer

To find the approximate total surface area of the truck and its bed, we need to calculate the surface area of both rectangular prisms (the cab section and the cargo section) and then combine the results.

  1. Cab Section:

    • Dimensions:
      • Length (L) = 4 feet
      • Width (W) = Depth (D) = 7.5 feet (depth is given as 7.5 feet)
      • Height (H) = 4 feet
    • Surface Area (SA) of a rectangular prism is given by the formula: \[ SA = 2(LW + LH + WH) \]
    • Plugging in the values for the cab section: \[ SA_{\text{cab}} = 2(4 \cdot 7.5 + 4 \cdot 4 + 7.5 \cdot 4) \] \[ = 2(30 + 16 + 30) = 2(76) \] \[ = 152 \text{ ft}^2 \]
  2. Cargo Section:

    • Dimensions:
      • Length (L) = 15 feet
      • Width (W) = 7.5 feet
      • Height (H) = 7.5 feet
    • Surface Area of the cargo section is calculated similarly: \[ SA_{\text{cargo}} = 2(15 \cdot 7.5 + 15 \cdot 7.5 + 7.5 \cdot 7.5) \] \[ = 2(112.5 + 112.5 + 56.25) = 2(281.25) \] \[ = 562.5 \text{ ft}^2 \]
  3. Total Surface Area:

    • Combining both surface areas: \[ SA_{\text{total}} = SA_{\text{cab}} + SA_{\text{cargo}} \] \[ = 152 + 562.5 = 714.5 \text{ ft}^2 \]

Therefore, the approximate total surface area of the truck and its bed is 714.5 ft².

The correct response from the provided options is 714.5 ft.².