Three different shapes of the same mass are cut from a sheet of iron as shown in the figure given below. Identify the shape with the highest density. Give reason.

All three pieces—the disc, the square, and the L-section—have exactly the same density.
Density is an intrinsic property of a material. For a given substance (here, iron) it depends only on the material's nature, not on the object's shape or size. Since each piece is cut from the same sheet of iron, their density remains the constant density of iron, regardless of how that mass is distributed geometrically.