dclbydalpha
thanks a lot mate ...helped me understand it a lot better ....lets see
here is what i got from your answer....the surface is flatter at the poles this means to make an angle of 1 degree at the center of the oblate spheroid we need to have a higher distance (presuming we are drawing perfect perpendiculars to the flat surface of the earth so that they intersect at the center of the earth)
this is because of the flatness of the earth so if we were to draw perpendiculars at an early point then they would intersect at a distance greater than the distance of the center of the oblate spheroid.