Can't quite see the side length on prism a but I think it says 4 so I'm going with it!
What we need to do is find the volume of each of the rectangular prisms, then add them together.
The formula for the volume of a rectangular prism is V = L × W × H
Prism A:
We have height and length but not width...since the back side of both prisms is 9, we can subtract the front side of prism b. 9 - 5 = 4 so...
v = 8 × 4 × 4 = 128 cm^3
Prism B
This prism is missing the width, but we can subtract the sides given on prism a... side 8 - 7 = 1 to find the missing width of prism b.
v = L × W × H
v = 5 × 1 × 4 = 20 cm^3
Now add the 2 volumes together...
128 + 20 = 148 cm^3 for total volume of the figure.
