Ok sir, understood.
If i want area of circle as 2000 sq.cm, using formula ∏r2, we can get radius as .2524 m
Then the volume for 15 m height will be ∏r2h, so volume is 3000 litres.
Since density of 1 litre water is almost equal to 1 kilogram
Weight(mg) will be 3000 * 9.8 = 29400 / 2000...