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 ...

Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and develop students' reasoning with properties of different classes of triangles to ...

Help children to use, discuss and think about shapes in mathematical terms with suggestions from Sheila Ebbutt and Carole Skinner. Shapes of things we can see or touch are mostly too complex to ...