Answer:
829.5 cubic units
Explanation:
When a rectangle is rotated about the line that is parallel to one of its sides, then a hollow cylinder is formed.
Inner radius = r = 4 units
Outer radius = R = 4 +3 = 7 units
h = 8 units
Volume of the hollow cylinder = π (R² - r²)*h
= π( 7² - 4²) * 8
= π * ( 49 - 16)* 8
= 3.142 * 33 *8
= 829.48
= 829.5 cubic units