2D shapes are flat, plane shapes. Triangles have three sides and three angles that add up to 180°. Quadrilaterals have four sides and four angles that add up to 360°. Constructing triangles Learn how ...

Two-dimensional (2D) shapes are completely flat. They have two dimensions – length and width. A polygon is a closed 2D shape with straight sides that meet at vertices. Polygons can be regular or ...