Two-dimensional (2D) shapes are completely flat. They cannot be picked up. A polygon is a 2D shape with straight sides that meet at vertices. Polygons have names that show the number of sides they ...

When you draw a shape, think about: How many sides it has. How long each side is. How many angles or corners it has. The type of angles it has - obtuse, acute or right angles. Use your ruler to ...

Two-dimensional materials are substances with a thickness of a few nanometres or less. Electrons in these materials are free to move in the two-dimensional plane, but their restricted motion in the ...

# classification porblem non-separable, which is a common situation in # real-world applications.