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. 2D shapes can be found printed in a book or on a website. 2D shapes have sides and corners. A rectangle has 4 straight sides and 4 corners. A square is ...