ANSWER
![3840 {m}^(3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/huvxyqo9rfuin3gmene3n8xkplcteo078a.png)
EXPLANATION
The total amount of space is the volume of the composite solid.
We find the volume of the rectangular prism and add it to the volume of the triangular prism.
The total amount of space inside the museum is:
![=l * b * h + (1)/(2) * base * height * height \: of \: triangular \: prism](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qhnm1malwuzi8875cxhv8eppwb8u3o7yuv.png)
![= 30 * 12 *1 0 + 0.5 * 12 * 4 * 10](https://img.qammunity.org/2020/formulas/mathematics/middle-school/3kf2le3om3zffnejonly16wcj0uziy90pa.png)
![= 360 0 + 240](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7zc45uzxs3b2ymocmn8n72lrkkza5lc8lb.png)
![= 3840 {m}^(3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gbjcl9zvtxjrdeoe599tmchw7qthg0og81.png)
Therefore,the total amount of space inside the museum is 3,840 cubic meters.