Check the picture below.
the volume of a rectangular prism is just the product of its 3 dimensions, so the volume of those two there is 4*9*6 and 3*6*5.
so the volume for the composite figure is just the sum of those two products.
the volume of a rectangular prism is just the product of its 3 dimensions, so the volume of those two there is 4*9*6 and 3*6*5.
so the volume for the composite figure is just the sum of those two products.