Assuming it's breadth is 4 1/2 m.
Assuming it's length is 8 1/4 m.
Assuming it's height is 6 1/2 m
Then the volume of a rectangular prism is given as l x b x h. Which means we multiply all the sides by one another. From my assumption of values, we have that 8 1/4 x 4 1/2 x 6 1/2, and this gives us 241.3125 m³ or 241.31