主题：【原创】在一个园上任点三点,求为锐角三角形的概率 (My answer) -- 地下室

A, B, C are three random points on the circle. Use two diameters to divide the circle into four areas (one horizontal and one vertical). Assume A is at the bottom of the vertical line. Then B, C points have the following distribution:

B C Triangle

1 1 A

1 2 A

1 3 A

1 4 O

2 1 A

2 2 A

2 3 O

2 4 A

3 1 A

3 2 O

3 3 O

3 4 O

4 1 O

4 2 A

4 3 O

4 4 O

O/T = 1/2; A/T = 1/2