1.
\[ c=\sqrt{a^2+b^2-2ab\cos60^\circ},\qquad S=\frac12ab\sin60^\circ \]
- \(a=8\text{ см},\,b=18\text{ см}\):
\[ c=\sqrt{244}=2\sqrt{61}\approx15{,}62\text{ см}, \qquad S=36\sqrt3\approx62{,}35\text{ см}^2. \]
- \(a=7\text{ см},\,b=12\text{ см}\):
\[ c=\sqrt{109}\approx10{,}44\text{ см}, \qquad S=21\sqrt3\approx36{,}37\text{ см}^2. \]
2.
- \(a=8,\ b=5,\ \gamma=65^\circ\):
\[ c\approx7{,}43,\qquad \alpha\approx77{,}4^\circ,\qquad \beta\approx37{,}6^\circ. \]
- \(a=9,\ b=8,\ \gamma=56^\circ\):
\[ c\approx8{,}03,\qquad \alpha\approx68{,}3^\circ,\qquad \beta\approx55{,}7^\circ. \]
