Answer
(a) $60,501,000ft^3$
(b) $a^2h$ or $b^2h$
(c) Yes, see explanations.
Work Step by Step
(a) Given $h=200ft, b=756ft, a=314ft$, use the formula, we have:
$V=\frac{1}{3}(200)(314^2+314\cdot 756+756^2)=60,501,000ft^3$
(b) When $a=b$, the resulting shape will be a rectangular prism with a square base. The volume will be the product of three sides, that is $V=a^2h=b^2h$
(c) Use the formula with $a=b$, we have $V=\frac{1}{3}h(3a^2)=a^2h=b^2h$ which is the same as in (b).
