Question

when we throw some water into the sky ,then the water bubble's tale circular shape . Why do they take that shape why cant they take the other?​

Answer 1

because it feel pressure from all direction

Answer 2

The drop takes this shape because water molecules tend to stick to each other. So, when not confined by a container, and with nothing around it to distort its shape, a very tiny water drop is perfectly round like a ball because the water molecules are pulling inward toward each other. 

If the drop is larger like a raindrop in free-fall, it has a domed top and a semi-flattened bottom because as it falls it must push the air out of its way. That "upward" push of the air being displaced causes the falling drop to have a rather flattened bottom. 

Contrary to popular misconception, a free-falling raindrop is not shaped like a teardrop -- round on the bottom and pointy on top.
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