\[\boxed{\mathbf{751\ (751).}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[a)\ S = 8^{2} - 4\pi \cdot 1^{2} = 64 -\]
\[- 4 \cdot 3,14 = 64 - 12,56 =\]
\[= 51,\ 44\ см^{2}.\]
\[\textbf{б)}\ S = \pi \cdot 3^{2} - 2 \cdot 1^{2} - 1 \cdot 2 -\]
\[- \frac{1}{2} \cdot 2 \cdot 1 = 9\pi - 2 - 2 - 1 =\]
\[= 9 \cdot 3,14 - 5 = 28,26 - 5 =\]
\[= 23,26\ см^{2}.\]