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 ...

Find out about regular 2D shapes and irregular polygons. Types of triangle Find out about scalene, equilateral, isosceles and right-angled triangles. Parts of a circle Discover the features of a ...

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 ...