Geometric Figures

　　If a point is selected at random inside a geometric figure, then the probability that the selected point lies inside a particular region is the ratio of their areas:

　　area of the particular region inside the figure/area of the whole figure.

　　Example: 

　　The probability that a randomly selected point within the square lies inside the circle=area of circle/area of square=∏r2/(4r2)= ∏/4.

　　Remember:

　　If the particular region is not completely inside the figure, then use only the area that is inside the figure.