Question

how can we measure the area of irregular solid​

Answer 1

When a solid is completely immersed in a liquid, displace the same volume of liquid as that of the solid. So take a cylinder, with known diameter, having scale leveling on it. Note down the height of the liquid without the solid and with the solid. Take the difference of them and calculate the volume of the raised liquid. That will be the volume of the solid.

How satisfied are you