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 ...

Two-dimensional (2D ... shapes and count the sides on each. Can you see both shapes have 6 sides, so both shapes are hexagons. What is different about the two shapes? All the sides on the first ...