Probability is the ratio of the area of triangle to the area of semicircle. =2/π。

(2) Eight points (1, 1) (1, 2) (2,2) (-1,1) meet the requirements.

Shaded areas are (1, 1) (2, 1) (- 1, 1) (-2, 1).

The probability is c 4 1 c 4 1 /C 42 =4/7. The answer is for reference only.