ALEX Classroom Resource

Students:

• Sort two-dimensional figures based on angle sizes or presence of parallel and/or perpendicular lines.

Example: Given a group of regular polygons, sort shapes into categories based on angle size as well as presence of parallel lines.
• Classify and name shapes using more than one characteristic.
• Identify a right triangle by labeling the right angle.

Students know:

• Two lines are parallel if they never intersect and are an equal distance apart.
• Two lines are perpendicular if they are at right angles to each other.
• A right triangle is a triangle that has one right angle.

Students are able to:

• Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines.
• Classify two-dimensional figures based on the presence or absence of angles of a specified size.
• Identify right triangles.

Students understand that:

• shapes are categorized based on attributes they possess in common such as angle size, side length, side relationships (parallel and perpendicular).

Learning Objectives:
M.4.28.1: Define right angle.
M.4.28.2: Recognize that shapes in different categories (e.g., rhombuses, rectangles, and others) may share attributes (e.g., having four sides), and that the shared attributes can define a larger category (e.g., quadrilaterals).
M.4.28.3: Recognize rhombuses, rectangles, and squares as examples of quadrilaterals, and draw examples of quadrilaterals that do not belong to any of these subcategories.
M.4.28.4: Recognize and draw shapes having specified attributes such as a given number of angles or a given number of equal faces.
M.4.28.5: Identify triangles.