Teaching about angles

Angles all around

• Angles are found all around us

Existing syllabus

• The angles concept is based on early ideas of corners.

• Emphasis on naming angles NOT understanding the amount and direction of turning of an angle.

• Sharp and blunt angles.

• Use of a protractor caused confusion.

Teaching about anglesStage 2

• Angles are used to describe: – the shape of a corner– direction– the amount of turning or opening– an inclination or slope

• Because angles arise in different ways in different situations, the topic can be difficult for students.

• Developing a sound understanding of angles is vital for further understandings in geometry.

Mathematics K - 62002

• In Stage 1 students identify corners as angles.

• Angles are compared by superimposing.

Mathematics K- 62002

Stage 2

• Recognise openings, slopes and turns as angles.

• Describe angles using everyday language and the term right.

• The students need practical experiences of creating, identifying and describing a range of angles.

Mathematics K- 62002Stage 3

• Classify angles as acute, obtuse, reflex, straight or a revolution.

• Measure angles in degrees and use the symbol, ° for degrees.

• Construct angles using a protractor.

Teaching about anglesStage 2

• Many students have difficulty in identifying and describing angles.

• When comparing the size of two angles, students are often confused by the length of the arms, and don’t measure the amount of turning.

Teaching about anglesStage 2

• The Teaching about angles, Stage 2 resource provides support for teachers in implementing the new K -6 syllabus.

• There are assessment tasks that can be used prior to and after the implementation of a sequence of lessons on angles.

• The lessons provide experiences in many different angles the students encounter in varied situations.

Teaching about anglesStage 2

• There are different sequences of lessons suggested.

• A Glossary is on page 11.

• Some activity sheets are provided to use with the lessons.

Teaching about anglesStage 2

Two-line angles• Both arms of the angle are visible.• Found in the corners of geometrical figures, angles

made by human limbs, corners and intersections in our environment.

Teaching about anglesStage 2

One-line angles• Only one arm of the angle is clearly visible.• Includes doors, hands of a clock, sloping roofs,

or slope of an incline.

Teaching about anglesStage 2

No-line angles• Neither arm of the angle is visible.• Examples are a ball rebounding from a wall or a

light reflecting from a mirror.

Teaching about anglesStage 2

• Students use a bent straw to measure angles.

Teaching about anglesStage 2

• Angle testers are used to measure angles.

Teaching about anglesStage 2

• With the angle testers, the students discover the size of different angles.