Explore the properties of 2D and 3D shapes — sides, faces, edges and vertices.
Shapes are all around us and can be grouped into 2D (flat) and 3D (solid) shapes. Two-dimensional shapes have length and width but no depth — they are perfectly flat. Common 2D shapes include triangles (3 sides), quadrilaterals (4 sides — including squares, rectangles, rhombuses and trapeziums), pentagons (5 sides), hexagons (6 sides) and octagons (8 sides). A regular polygon has all sides equal and all angles equal. Three-dimensional shapes have three dimensions — length, width and depth. We describe them using faces (flat or curved surfaces), edges (where two faces meet) and vertices (corner points). A cube has 6 faces, 12 edges and 8 vertices. A cylinder has 2 flat circular faces and 1 curved surface. A sphere has 0 edges, 0 vertices and 1 curved face. Knowing the properties of shapes helps in design, engineering and art.