Let polar equation r = 2a ( 1 - sin θ ), where a is a positive constant.
Determine polar coordinates of points P and Q in which curve intersects circle r = a.
Illustrate that area of finite region bounded by minor arc PQ of circle r = a and arcs OP, OQ of thecurve, where O is pole, is (21√3 - 10π)a2/6.