Mathematics / Year 9 / Measurement and Geometry / Pythagoras and trigonometry

Curriculum content descriptions

Apply trigonometry to solve right-angled triangle problems (ACMMG224)

Elaborations
  • understanding the terms adjacent and opposite sides in a right-angled triangle
  • selecting and accurately using the correct trigonometric ratio to find unknown sides (adjacent, opposite and hypotenuse) and angles in right-angled triangles
General capabilities
  • Literacy Literacy
  • Numeracy Numeracy
ScOT terms

Trigonometric ratios,  Right angled triangles

Interactive

Laptop wrap: Talking trigonometry

In this laptop-friendly resource, students consolidate their understanding of trigonometry by investigating practical applications of the ratios, highlighting the process they used to find a solution.

Interactive

Renovate, Calculate!

A student resource that explores the use of mathematics in the trades. Highly interactive investigations into ratio, areas of special quadrilaterals and right-angled trigonometry.

Downloadable

Introduction to trigonometry

These lesson plans guide the teacher on how to introduce trigonometry to students through an investigation of similar triangles.

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Work sample Year 9 Mathematics: Similar triangles

This work sample demonstrates evidence of student learning in relation to aspects of the achievement standards for Year 9 Mathematics. The primary purpose for the work sample is to demonstrate the standard, so the focus is on what is evident in the sample not how it was created. The sample is an authentic representation ...

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Mathematics of bushfire

In these classroom activities students will be introduced to some of the basic mathematical principles that underpin wildfire science, with an emphasis on how theoretical concepts are used to aid our understanding of the real world, and bushfire in particular. They will learn about the complexities of the fire management ...

Video

Mystery man Pythagoras meets his match

What do you know about Pythagoras? Join Vi Hart as she not only explains his theorem but raises some legends about his dark past! Follow Vi's timeline of famous mathematicians to find out in which century Pythagoras lived. See how Vi shows a proof of his theorem and raises what was a big dilemma for Pythagoras: the irrational ...

Interactive

The geometer's warehouse

This web-based, multimedia resource focuses on the geometry of the Stage 4 and Stage 5 Mathematics syllabus. It comprises 70 dynamic html worksheets, each exploring a different outcome in Stage 4 and Stage 5 geometry.

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TIMES Module 22: Measurement and Geometry: scale drawings and similarity - teacher guide

This is a 41-page guide for teachers. It contains an introduction to scale drawings and similarity, and in particular the tests for triangles to be considered similar. Applications of similarity are included throughout the module.

Online

TIMES Module 22: Measurement and Geometry: introductory trigonometry - teacher guide

This is a 20-page guide for teachers containing an introduction to the three basic trigonometric ratios. A history of trigonometry concludes the module.

Downloadable

Operations: Foundation to Year 9

This comprehensive resource describes the progression of ideas that cover addition and subtraction of integers; multiplication and division of integers; the four operations with common and decimal fractions; and operation applications with percent, rate and ratio.

Video

MathXplosion, Ep 50: How to use a tetrahedron to solve the tree problem

How can you place four trees exactly the same distance apart from one other? By making a model! By using miniature trees to make a model of the problem, it becomes clear that a 2D solution is impossible. We learn how objects can help us visualise the problem situation, which in this case requires a 3D solution: a tetrahedron.

Video

My Five Cents: Why borrowing can cost you more

Think credit cards are basically free money? Gen Fricker will make you think again. Learn how interest rates and fees affect the money you borrow, and why they may be more expensive in the long run. Oh dear! Then test yourself with ASIC MoneySmart's "Things to think about" classroom exercises.  

Video

Maths inside bees and beehives

Bees are necessary for assisting many plants to produce the food we eat, including meat and milk. Colony collapse disorder, which describes the disappearance of beehives, could have catastrophic effects on food production. Australian scientists are applying their maths and science knowledge to build up a picture of a healthy ...

Video

Catalyst: Nautical Robots

How might you find out how much and where the Earth's oceans are warming? Watch the report by Ruben Meerman and discover how more than 3000 'nautical robots', known as argo floats, have been placed in the oceans to collect data on variations in temperature, pressure and salinity.

Video

Using maths to understand the universe

When completed, the Square Kilometre Array (SKA) project will be the largest and most capable radio telescope available to scientists. Radio telescopes like the SKA detect radio waves produced by events and objects in the furthest reaches of space, translating these waves into data and imagery that allow scientists to study ...

Online

TIMES Module 21: Number and Algebra: rates and ratios - teacher guide

This is a 17-page guide for teachers. This module introduces the idea of ratios and rates. Ratios are used to compare two quantities. The emphasis is usually on comparing parts of the whole. Rates are a measure of how one quantity changes for every unit of another quantity. It relates the ideas of ratios, gradient and fractions.

Online

TIMES Module 15: Measurement and Geometry: Pythagoras's theorem - teacher guide

This is a 24-page guide for teachers. It contains proofs of Pythagoras's theorem and its converse, applications of Pythagoras's theorem and a discussion of Pythagorean triads. A history of Pythagoras's theorem concludes the module.

Online

Similarity

This is a website designed for both teachers and students, which addresses similarity from the Australian Curriculum for year 9 students. It contains material on enlargement transformation and similar triangles. There are pages for both teachers and students. The student pages contain interactive questions for students ...

Online

Trigonometry

This is a website designed for both teachers and students, which addresses content on trigonometry from the Australian Curriculum for year 9 students. It contains material on working with the similarity of right-angled triangles, the three basic trigonometric ratios, and solving problems with trigonometry. There are pages ...

Video

MathXplosion, Ep 10: What is the strongest shape?

Are triangles really the strongest shapes ever? If so, why? Learn how and why right-angled and equilateral triangles have been used in engineering, architecture and design through the ages.