AC9M4M04

Measurement > Angle

Australian Curriculum Version 9 Says:

Estimate and compare angles using angle names including acute, obtuse, straight angle, reflex and revolution, and recognise their relationship to a right angle.

What this means

Students will need to be familiar with some benchmark angles e.g. right angles (a corner) to help classify other angle types.

  • A right angle measures 90°. e.g. where a wall meets the floor is a right angle.
  • Classifications: right angle (90°), acute angle (less than 90°), obtuse angle (greater than 90° but less than 180°), straight angle (180°), reflex angle (greater than 180° and less than 360°).
  • Links to the real world can be made by using spirit levels and set squares.

Tips

  • This does not mean using a protractor to measure angles. The focus is on estimating angle sizes using a right angle as a benchmark.
  • Look at a pair of scissors. Consider the angles made.

Click on image to Enlarge descriptor card.

Resources & Manipulatives

These Quick Curriculum Guides have been designed to take a look at the Australian Mathematics Curriculum (AC9), explain terminology and provide interpretations.

Narelle and I have used our professional judgement to put forward what is appropriate for students at this year level.

Authors: Dr Paul Swan & Narelle Rice
We would like to also thank Linda Marshall and David Dunstan for comments and assistance.

These documents serve as general advice only and do not take into account your specific needs and conditions. While best care has been taken in compiling these materials, mistakes may exist.
Australian Curriculum version 9 materials used under Creative Commons licence from ACARA. Readers should always refer back to the curriculum itself and the state-based curriculum that is relevant for you.

This document is copyright of A-Z Type (Dr Paul Swan). A copy of this document may be downloaded from www.drpaulswan.com.au.