where can I get the volume of this u-shaped diagram?

Answer:
Recall that the volume of a shaped diagram is given by the following formula:
[tex]\text{Volume}=BaseArea\times length\text{.}[/tex]Now, to compute the area of the given base, we will divide the figure as follows:
Then the area of the given figure is:
[tex]A=9\operatorname{cm}\times2\operatorname{cm}+6\operatorname{cm}\times2\operatorname{cm}+6\operatorname{cm}\times2\operatorname{cm}\text{.}[/tex]Simplifying the above result we get:
[tex]\begin{gathered} A=18cm^2+12cm^2+12cm^2, \\ A=42cm^2\text{.} \end{gathered}[/tex]Therefore the volume of the given u-shaped diagram is:
[tex]V=42cm^2\cdot7\frac{1}{2}cm=42cm^2\cdot7.5\operatorname{cm}.[/tex]Simplifying the above result we get:
[tex]V=315cm^3\text{.}[/tex]The volume of the given diagram is 325 cubic centimeters.