Pick up the incorrect statement from the following :

• The C.G. of a circle is at its centre
• The C.G. of a triangle is at the intersecton of its medians
• The C.G. of a rectangle is at the intersection of its diagonals
• The C.G. of a semicircle is at a distance of r/2 from the centre
• The C.G. of an ecllipse is at the intersection of axes.