## Algebra and Trigonometry 10th Edition

(a) $\pi h(R+r)(R-r)$ (b) $\ 2 \pi h \frac{R+r}{2}(R-r)\ = \pi h(R+r)(R-r)$
(a) when factored, $$\pi R^{2}h - \pi r^{2}h = \pi h(R+r)(R-r)$$ (b) Average Radius: $\frac{R+r}{2}$ Thickness of the shell: $R-r$ $2\pi h (average)(thickness) = \pi h(R+r)(R-r)\ 2 \pi h \frac{R+r} {2}(R-r)\ = \pi h(R+r)(R-r)$