Mathematics / Year 4 / Measurement and Geometry / Geometric reasoning

View on Australian Curriculum website Australian Curriculum, Assessment and Reporting Authority
Curriculum content descriptions

Compare angles and classify them as equal to, greater than, or less than, a right angle (ACMMG089)

  • creating angles and comparing them to a right angle using digital technologies
General capabilities
  • Literacy Literacy
  • Numeracy Numeracy
  • Critical and creative thinking Critical and creative thinking
ScOT terms

Obtuse angles,  Reflex angles,  Right angles,  Acute angles

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Year level 3-4
Resource type
Learning area Mathematics
Interactive Resource

Angles (estimating angle size)

This is a six-page HTML resource about solving problems involving estimating angle size. It contains one video and three questions, two of which are interactive. The resource discusses and explains solving problems to reinforce students' understanding.

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Right-angle detective

Do you know what a right angle is? See how many right angles you can find in a drawing of a house. Have you heard of symmetry? It's when something can be divided into two parts and each part is a mirror image of the other. See an example where we compare the images of two houses.

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Daredevil geometry

What does a daredevil jumps rider need to know about geometry? Find out as we discover angles for take off and for landing. But before we do that sit down for some angles basics! A good place to start is angles of turn through a circle from a 1/4, 1/2, 3/4, all the way to one full turn. See how many each represents as an angle.

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Right angle or acute angle?

What's the difference between a right angle and an acute angle? Find out!

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Angles are nice but are they cute?

Ever heard of acute angles? What about obtuse angles? Find out which is bigger than a right angle and which is smaller. See how to mark a right angle. And what's a straight angle?

Interactive Resource

Free protractor

This iPad app is a digital 180-degree protractor. Angles can read from the right or left of the perpendicular, and acute and obtuse angles are shown in different colours. Angles can be set by moving the pointer or using the keyboard to enter the required degree of angle. The angle can also be locked when taking readings.


Mixed-Up Maths

Join our host, Ed, as he finds himself in all types of situations where only his knowledge of Maths can help him. From saving the planet from Aliens, to creating a superhero that can stop a strawberry milkshake tidal wave. From searching for buried treasure, to jumping like a daredevil, or planning the greatest circus party ...