r1, r2 > 0 and if C1, C2 are centres of the two circles having only two common tangents and C1C2 = r1 + r2 then which of the following is correct
1
r1, r2 are the radii of the two circles
2
The common chord may divide the line joining the centres in the ratio r1 ∶ r2
3
r1, r2 are always the distances of the centres from the common tangent of the two circles
4
external centre of similitude divides C1C2 in the ratio r1 ∶ r2