Why does changing the shape of an object not affect its density

Density  is a characteristic property of a substance, material or object and is defined as the relationship between the mass and volume of that specific substance or material.

This is due the fact that any object or material has mass and volume, however the mass of different substances occupy different volumes.  As shown in the following equation:

Where:

is the mass of the object

is the volume of the object

This is why changing the shape of an object not affect its density.