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Classifying shapes by line properties

PROCEDURAL
Mathematics›Geometry|Ages 9—10|ID: mt_r8c43QB6wx

Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or angles of a specified size; recognise right triangles as a category

Mastery Evidence

  • Sort a set of quadrilaterals into those with parallel sides and those without
  • Identify which triangles in a set are right triangles
  • Classify shapes that have both perpendicular and parallel sides

Assessment Prompt

“If you show [child] a mixed set of triangles and quadrilaterals, can they sort them into groups — like "shapes with at least one right angle" or "shapes with parallel sides" — and explain their reasoning?”

Prerequisites2

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  • Lines, Rays & Angles hard

    Must draw/identify geometric elements before classifying shapes by them

    • Types of angles hard

      Y4 acute/obtuse angle identification is prerequisite to drawing and labelling angle types

      • Right Angles & Turns hard

        Identifying right angles and greater/less than right angle is prerequisite to naming acute/obtuse

        • Understanding angles hard

          Identifying right angles requires understanding what an angle is

          • 2-D shapes (age 6+) soft

            Understanding angles as shape properties requires knowing basic shape properties

            • Angles in triangles (age 6+) soft

              Understanding defining attributes supports describing shape properties formally

              • 2-D shapes hard

                Distinguishing defining vs non-defining attributes requires knowing common 2-D shape names first

              • 3-D shapes (age 5+) hard

                Identifying defining attributes builds on informal analysis and comparison of shapes

                • 2-D shapes hard

                  Analysing and comparing shapes requires being able to name them first

                • 3-D shapes hard

                  Analysing 3-D shapes requires recognising and naming them

            • 2-D shapes hard

              Describing properties of 2-D shapes (sides, symmetry) requires knowing the shapes first

            • 3-D shapes (age 5+) hard

              Formal property description extends informal analysis of sides and vertices

              • 2-D shapes hard

                Analysing and comparing shapes requires being able to name them first

              • 3-D shapes hard

                Analysing 3-D shapes requires recognising and naming them

          • Position, direction, and movement hard

            Recognising angles as turns extends Y2 work on quarter/half/three-quarter turns

            • Positional Language hard

              Position/direction vocabulary with right angles extends basic positional language

            • Turns & Directions hard

              Right-angle turns (clockwise/anti-clockwise) build directly on whole/half/quarter turns from Year 1

              • What Is a Half? soft

                Understanding half and quarter turns benefits from the concept of halves and quarters

                • Division as equal sharing hard

                  Finding a half requires equal sharing into 2 groups — a division concept

                  • Subtraction as taking away or separating hard

                    Division as equal sharing/grouping requires understanding subtraction as taking away/separating

                    • How Many in Total? hard

                      Understanding subtraction as taking away requires knowing numbers represent quantities (cardinality)

                      • One-to-one counting hard

                        Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

              • Positional Language hard

                Describing movement and turns builds on positional language

        • Types of angles (age 8+) soft

          Identifying right angles and turns is supported by the convention of marking right angles with a small square

        • Position, direction, and movement hard

          Right angles as quarter turns extends Y2 turn vocabulary

          • Positional Language hard

            Position/direction vocabulary with right angles extends basic positional language

          • Turns & Directions hard

            Right-angle turns (clockwise/anti-clockwise) build directly on whole/half/quarter turns from Year 1

            • What Is a Half? soft

              Understanding half and quarter turns benefits from the concept of halves and quarters

              • Division as equal sharing hard

                Finding a half requires equal sharing into 2 groups — a division concept

                • Subtraction as taking away or separating hard

                  Division as equal sharing/grouping requires understanding subtraction as taking away/separating

                  • How Many in Total? hard

                    Understanding subtraction as taking away requires knowing numbers represent quantities (cardinality)

                    • One-to-one counting hard

                      Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

            • Positional Language hard

              Describing movement and turns builds on positional language

    • Parallel and perpendicular lines hard

      Y3 horizontal/vertical/perpendicular/parallel lines is prerequisite to drawing and identifying them formally

      • Right Angles & Turns hard

        Perpendicular lines require understanding right angles

        • Understanding angles hard

          Identifying right angles requires understanding what an angle is

          • 2-D shapes (age 6+) soft

            Understanding angles as shape properties requires knowing basic shape properties

            • Angles in triangles (age 6+) soft

              Understanding defining attributes supports describing shape properties formally

              • 2-D shapes hard

                Distinguishing defining vs non-defining attributes requires knowing common 2-D shape names first

              • 3-D shapes (age 5+) hard

                Identifying defining attributes builds on informal analysis and comparison of shapes

                • 2-D shapes hard

                  Analysing and comparing shapes requires being able to name them first

                • 3-D shapes hard

                  Analysing 3-D shapes requires recognising and naming them

            • 2-D shapes hard

              Describing properties of 2-D shapes (sides, symmetry) requires knowing the shapes first

            • 3-D shapes (age 5+) hard

              Formal property description extends informal analysis of sides and vertices

              • 2-D shapes hard

                Analysing and comparing shapes requires being able to name them first

              • 3-D shapes hard

                Analysing 3-D shapes requires recognising and naming them

          • Position, direction, and movement hard

            Recognising angles as turns extends Y2 work on quarter/half/three-quarter turns

            • Positional Language hard

              Position/direction vocabulary with right angles extends basic positional language

            • Turns & Directions hard

              Right-angle turns (clockwise/anti-clockwise) build directly on whole/half/quarter turns from Year 1

              • What Is a Half? soft

                Understanding half and quarter turns benefits from the concept of halves and quarters

                • Division as equal sharing hard

                  Finding a half requires equal sharing into 2 groups — a division concept

                  • Subtraction as taking away or separating hard

                    Division as equal sharing/grouping requires understanding subtraction as taking away/separating

                    • How Many in Total? hard

                      Understanding subtraction as taking away requires knowing numbers represent quantities (cardinality)

                      • One-to-one counting hard

                        Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

              • Positional Language hard

                Describing movement and turns builds on positional language

        • Types of angles (age 8+) soft

          Identifying right angles and turns is supported by the convention of marking right angles with a small square

        • Position, direction, and movement hard

          Right angles as quarter turns extends Y2 turn vocabulary

          • Positional Language hard

            Position/direction vocabulary with right angles extends basic positional language

          • Turns & Directions hard

            Right-angle turns (clockwise/anti-clockwise) build directly on whole/half/quarter turns from Year 1

            • What Is a Half? soft

              Understanding half and quarter turns benefits from the concept of halves and quarters

              • Division as equal sharing hard

                Finding a half requires equal sharing into 2 groups — a division concept

                • Subtraction as taking away or separating hard

                  Division as equal sharing/grouping requires understanding subtraction as taking away/separating

                  • How Many in Total? hard

                    Understanding subtraction as taking away requires knowing numbers represent quantities (cardinality)

                    • One-to-one counting hard

                      Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

            • Positional Language hard

              Describing movement and turns builds on positional language

      • Positional Language soft

        Horizontal/vertical builds on positional vocabulary

  • Understanding angles (age 8+) hard

    Y4 quadrilateral classification supports classifying by lines/angles

    • 2-D shapes (age 6+) hard

      Identifying 2D shape properties is prerequisite to classifying by shared attributes

      • Angles in triangles (age 6+) soft

        Understanding defining attributes supports describing shape properties formally

        • 2-D shapes hard

          Distinguishing defining vs non-defining attributes requires knowing common 2-D shape names first

        • 3-D shapes (age 5+) hard

          Identifying defining attributes builds on informal analysis and comparison of shapes

          • 2-D shapes hard

            Analysing and comparing shapes requires being able to name them first

          • 3-D shapes hard

            Analysing 3-D shapes requires recognising and naming them

      • 2-D shapes hard

        Describing properties of 2-D shapes (sides, symmetry) requires knowing the shapes first

      • 3-D shapes (age 5+) hard

        Formal property description extends informal analysis of sides and vertices

        • 2-D shapes hard

          Analysing and comparing shapes requires being able to name them first

        • 3-D shapes hard

          Analysing 3-D shapes requires recognising and naming them

    • Angles in triangles (age 7+) hard

      Recognising shapes by attributes is prerequisite to quadrilateral hierarchy classification

      • Angles in triangles (age 6+) hard

        Drawing shapes by attributes extends understanding defining vs non-defining attributes

        • 2-D shapes hard

          Distinguishing defining vs non-defining attributes requires knowing common 2-D shape names first

        • 3-D shapes (age 5+) hard

          Identifying defining attributes builds on informal analysis and comparison of shapes

          • 2-D shapes hard

            Analysing and comparing shapes requires being able to name them first

          • 3-D shapes hard

            Analysing 3-D shapes requires recognising and naming them

      • 2-D shapes (age 6+) hard

        Identifying pentagons, hexagons, quadrilaterals extends knowing 2-D shape properties

        • Angles in triangles (age 6+) soft

          Understanding defining attributes supports describing shape properties formally

          • 2-D shapes hard

            Distinguishing defining vs non-defining attributes requires knowing common 2-D shape names first

          • 3-D shapes (age 5+) hard

            Identifying defining attributes builds on informal analysis and comparison of shapes

            • 2-D shapes hard

              Analysing and comparing shapes requires being able to name them first

            • 3-D shapes hard

              Analysing 3-D shapes requires recognising and naming them

        • 2-D shapes hard

          Describing properties of 2-D shapes (sides, symmetry) requires knowing the shapes first

        • 3-D shapes (age 5+) hard

          Formal property description extends informal analysis of sides and vertices

          • 2-D shapes hard

            Analysing and comparing shapes requires being able to name them first

          • 3-D shapes hard

            Analysing 3-D shapes requires recognising and naming them

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