Multiple Attributes of 2D Shapes and 3D Objects
Sorting by two attributes at once is an early form of logical AND reasoning. A square belongs in the group of shapes with 4 sides AND the group of shapes with equal angles. Two-attribute sorting forces students to hold two criteria in mind simultaneously and find shapes that satisfy both. This logical structure underlies classification in science, database querying, and all of formal mathematics.
Two-attribute sorting and the Venn diagram
A Venn diagram with two overlapping circles represents two attributes simultaneously. Shapes in the left circle satisfy attribute 1. Shapes in the right circle satisfy attribute 2. Shapes in the overlap satisfy both. Shapes outside both circles satisfy neither. This four-region structure is the logic of AND, OR, and NOT made visible.
Constructing shapes from descriptions
Given: a shape with 4 equal sides and 4 right angles. Students construct it on a geoboard or dot paper. This reverses the usual direction: instead of seeing a shape and describing it, students must generate a shape from a description. Construction reveals whether students truly understand which attributes are essential and which are incidental.
Ovoids, U-forms, and formline art
Northwest Coast formline art uses ovoids (modified rounded rectangles), U-forms (open curves), and split U-forms as its primary design vocabulary. The BC curriculum highlights these as examples of shapes reflected in the natural environment and in cultural art. Students who analyse formline designs are applying geometric attribute recognition to a rich and living artistic tradition.