\[a = 4\ см;b = 6\ см;\ \ \angle ab = \alpha.\]
\[1)\ S = 6\ см^{2}:\]
\[S = \frac{1}{2} \bullet 4 \bullet 6\sin\alpha\]
\[24 \bullet \sin\alpha = 12\]
\[\sin\alpha = \frac{1}{2}.\]
\[Ответ:\ \ да.\]
\[2)\ S = 14\ см^{2}:\]
\[S = \frac{1}{2} \bullet 4 \bullet 6\sin\alpha\]
\[24 \bullet \sin\alpha = 28\]
\[\sin\alpha = \frac{7}{6} > 1.\]
\[Ответ:\ \ нет.\]
\[3)\ S = 12\ см^{2}:\]
\[S = \frac{1}{2} \bullet 4 \bullet 6\sin\alpha\]
\[24 \bullet \sin\alpha = 24\]
\[\sin\alpha = 1.\]
\[Ответ:\ \ да.\]