determining gender by tail shape?

[pinkyglory123]

Question-I have three geese-two laying. Approx. a year old. Probably African/Chinese mix. Noticed today-not sure why I never did before, that while they were walking around-two had distinctly pointed tails and one had a squared off tail. Any significance to this differance. Obviously I have two females since they are laying-wondering if the third is a male.....