Решебник по геометрии 9 класс Мерзляк Задание 132

\[1)\ AB = 12\ см;AC = 9\ см;\angle A = 30{^\circ}:\]

\[S = \frac{1}{2}AB \bullet AC \bullet \sin{\angle A} =\]

\[= \frac{1}{2} \bullet 12 \bullet 9 \bullet \sin{30{^\circ}} =\]

\[= 54 \bullet \frac{1}{2} = 27\ см^{2}.\]

\[Ответ:\ \ 27\ см^{2}\text{\ .}\]

\[2)\ AC = 3\ см;BC = 6\sqrt{2}\ см;\angle C = 135{^\circ}:\]

\[S = \frac{1}{2}AC \bullet BC \bullet \sin{\angle C} =\]

\[= \frac{1}{2} \bullet 3 \bullet 6\sqrt{2} \bullet \sin{135{^\circ}} =\]

\[= 9\sqrt{2} \bullet \frac{\sqrt{2}}{2} = 9\ см^{2}\text{.\ }\]

\[Ответ:\ \ 9\ см^{2}.\]