[MA2019] (5) 22 :
22. Classify quadrilaterals in a hierarchy based on properties. [MA2019] (5) 21 :
21. Classify triangles according to side length (isosceles, equilateral, scalene) and angle measure (acute, obtuse, right, equiangular). [MA2019] (5) 23 :
23. Explain that attributes belonging to a category of two-dimensional figures also belong to all subcategories of that category.
Example: All rectangles have four right angles, and squares have four right angles, so squares are rectangles.