Find the volume of the rectangular prism. I thought I understood the lesson.

To determine the volume of the rectangular prism;
[tex]Volume=lengthXbreadthXheight[/tex][tex]Volume\text{ = 6 }X\text{ 1}\frac{1}{2}\text{ }X\text{ 4}\frac{1}{2}[/tex][tex]Volume=\text{ 40.5 ft}^3[/tex]The volume of the rectangular prism is 40.5 ft³