Respuesta :

THe bottom rectangular prism  has volume 8*7.5*7 =  420 cu ft

The top triangular prism  has a volume of 1/2 * 7 * 7.5 * 8 =  210 cu ft

Total volume = 420+210  = 630 cu ft

Answer:

[tex]V=630ft^3[/tex]

Step-by-step explanation:

This solid is composite by a triangular prism and a rectangular prism. So, let:

[tex]V_1=Volume\hspace{3}of\hspace{3}the\hspace{3}rectangular\hspace{3}prism\\V_2=Volume\hspace{3}of\hspace{3}the\hspace{3}triangular\hspace{3}prism[/tex]

Hence, the volume of the composite solid is:

[tex]V=V_1+V_2[/tex]

The volume of the rectangular prism is given by:

[tex]V_1=l*w*h[/tex]

Where:

[tex]l=length=8ft\\w=width=7.5ft\\h=height=7ft[/tex]

So:

[tex]V_1=8*7.5*7=420ft^3[/tex]

The volume of the triangular prism is given by:

[tex]V_2=\frac{1}{2} l*b*h[/tex]

Where:

[tex]l=Distance\hspace{3} between\hspace{3} the\hspace{3} triangular \hspace{3}faces=8ft\\b=length\hspace{3}of\hspace{3} one\hspace{3} side \hspace{3}of\hspace{3} the \hspace{3}triangle=7.5ft\\h=length \hspace{3} of \hspace{3} an \hspace{3}altitude \hspace{3} drawn \hspace{3} to \hspace{3} that \hspace{3}side=7ft[/tex]

So:

[tex]V_2=\frac{8*7.5*7}{2} =210ft^3[/tex]

Therefore:

[tex]V=420ft^3+210ft^3=630ft^3[/tex]