Question

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An illustration shows a that is shaped like a rectangular prism with two triangular prisms placed on the top, one on each side. The width of the rectangular prism is 10 inches, and the height is 12 inches. The base length of the triangular prisms on the top of the house is 8 inches each. There is a 2-inch gap between the two triangular prisms. The perpendicular height of the triangular prisms is 6 inches. A window is drawn on the face of each triangular prism, and a door is drawn on the bottom center of the rectangular prism.

Write and solve an expression for the total volume of the dollhouse.(1 point)
Responses

264 in.3
264 in. cubed

2,640 in.3
2,640 in. cubed

2,400 in.3
2,400 in. cubed

3,120 in.3
3,120 in. cubed
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1 answer

To find the total volume of the dollhouse, we need to calculate the volume of both the rectangular prism and the two triangular prisms.

Volume of the Rectangular Prism

The volume \( V \) of a rectangular prism is given by the formula:

\[ V_{\text{rect}} = \text{length} \times \text{width} \times \text{height} \]

From the problem, the dimensions of the rectangular prism are as follows:

  • Width = 10 inches
  • Height = 12 inches
  • The length is not provided directly, but is implied by the bases of the triangular prisms. Each triangular prism has a base length of 8 inches, and since there is a 2-inch gap between the two triangular prisms (total gap is 2 inches), we can assume the length of the rectangular prism is the combined base lengths of the triangular prisms plus the gap.

Thus, the effective length of the rectangular prism can be calculated as follows:

Effective length = base length of triangular prism * number of triangular prisms + gap
= 8 inches + 2 inches = 10 inches

Now we can calculate the volume of the rectangular prism:

\[ V_{\text{rect}} = 10 , \text{in} \times 10 , \text{in} \times 12 , \text{in} = 1200 , \text{in}^3 \]

Volume of One Triangular Prism

The volume \( V \) of a triangular prism is given by the formula:

\[ V_{\text{tri}} = \frac{1}{2} \times \text{base} \times \text{height} \times \text{length} \]

For the triangular prisms, we have:

  • Base = 8 inches
  • Height (perpendicular height) = 6 inches
  • Length = 10 inches (the same as the rectangular prism)

Now we can calculate the volume of one triangular prism:

\[ V_{\text{tri}} = \frac{1}{2} \times 8 , \text{in} \times 6 , \text{in} \times 10 , \text{in} = 240 , \text{in}^3 \]

Total Volume of the Two Triangular Prisms

Since there are two identical triangular prisms, we multiply the volume of one triangular prism by 2:

\[ V_{\text{tri, total}} = 2 \times V_{\text{tri}} = 2 \times 240 , \text{in}^3 = 480 , \text{in}^3 \]

Total Volume of the Dollhouse

Now, we add the volumes of the rectangular prism and the two triangular prisms:

\[ V_{\text{total}} = V_{\text{rect}} + V_{\text{tri, total}} = 1200 , \text{in}^3 + 480 , \text{in}^3 = 1680 , \text{in}^3 \]

Conclusion

The total volume of the dollhouse is:

\[ \boxed{1680 , \text{in}^3} \]

Please check if all parameters are assumed correctly or if any values seem to differ, as the options you provided do not include 1680 in³.