How to drink all the tea from a cup

Of course

The mutt will always be below

Unless you shake it and get it to the top

And also it will be of the same shape as the liquid
(This is our key idea.)

So you tilt the glass, so you get the shape of a triangle.

You're still only drinking from the top

Until You reach the first mutt

Also, the shape of the triangle was elongated for a reason

[volume remains the same, but length differs]

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