Решебник по математике 9 класс. вероятность и статистика Высоцкий ФГОС Часть 2 Задание 200

\[\boxed{\mathbf{200.}}\]

\[\cup AB = \cup BC = \cup AC =\]

\[= \frac{360}{3} = 120{^\circ}.\]

\[\textbf{а)}\ 120{^\circ} = \frac{1}{3}окружности;\]

\[L_{\text{AB}} = L_{\text{BC}} = L_{\text{AC}} = \frac{2\text{πR}}{3};\]

\[P(X) = \frac{\frac{2\text{πR}}{3}}{2\text{πR}} = \frac{1}{3}.\]

\[\textbf{б)}\ \cup BC + \cup BA =\]

\[= 240{^\circ} = \frac{2}{3}окружности;\]

\[L_{BC + BA} = L_{BC + AC} =\]

\[= L_{AB + BC} = \frac{4\text{πR}}{3};\]

\[P(X) = \frac{\frac{4\text{πR}}{3}}{2\text{πR}} = \frac{2}{3}.\]