ALEX Classroom Resources

   View Standards     Standard(s): [MA2019] (0) 21 :

21. Analyze and compare two- and three-dimensional shapes, in different sizes and orientations, using informal language to describe their similarities, differences, parts (number of sides and vertices or "corners"), and other attributes.

Example: Having sides of equal length.

[MA2019] (0) 23 :

23. Use simple shapes to compose larger shapes.

Example: Join two triangles with full sides touching to make a rectangle.

Two-Headed Monster has arrived to demonstrate the rectangle shape. The problem is, they don't seem to know what a rectangle looks like. Instead, they pull out two triangles. They discover, however, that two triangles can be used to make one rectangle. This resource teaches shapes.