0 < x < y < 1 with f(x;y) = 0 for other x;y 4 A point (x;y) is said to be drawn \uniformly" from a set A ˆ R2 in the plane if the joint density function f(x;y) has some constant value c > 0 for (x;y) 2 A, and is zero outside A Let X and Y be the coordinates of a point