it is a net.
The net of a 3D shape
A net.
the net of a shape is how many sides of a shapeThe net of a solid shape is a flat arrangement of its faces faces which can be folded together to make the solid shape. See related links, below.
If you had a 3D shape made out of paper, that was all folded and taped together, and you pulled the tape off and layed the figure out flat, then you would get the net of the three dimensional solid.
A cylinder would fit the given description because it has two flat circular faces each side of a circular body.
A net for the 3D shape.
The net of a 3D shape
SQUARE
net
A square
A net.
The planet is basically globular itself. Flat maps are called projections. Projections involve distorting the real size and shape of the globular three dimensional shape to display a facsimile of it on a flat map which can be folded, stacked, filed, generally handled more conveniently
the net of a shape is how many sides of a shapeThe net of a solid shape is a flat arrangement of its faces faces which can be folded together to make the solid shape. See related links, below.
Flat model
The description given fits that of a triangle.
Flat round disk Apex(: KB
A cone would fit the given description