Читать книгу Probability and Statistical Inference - Robert Bartoszynski - Страница 50

The chord is uniquely determined by the angle (see Figure 2.2). These angles are chosen at random from the interval . It is clear that the length of the chord exceeds the side of the equilateral triangle if lies between and , so the answer to the question is .

Figure 2.2 First solution of Bertrand's problem.