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

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reSolve: Gradient and Tangent

This sequence of two lessons investigates gradient and angle by applying the tangent ratio to find the angles represented by a road sign or the angle of a street. In the first lesson, students research what a road grade is and determine the actual angle of a road given its grade. They then construct their own road sign ...

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.

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reSolve: Mathematical modelling: The steepest slopes on Baldwin St

In this sequence of three lessons, students measure and represent steepness in multiple ways, connect gradient to tangent, and consider how mathematical information is communicated to real audiences; using the context of Baldwin Street, the world’s steepest residential street. Key learning goals, pedagogical tools and design ...

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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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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 ...

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reSolve: Mechanical Linkages: Similar Triangles

This sequence of lessons explores the geometry of similar triangles using two real world objects: ironing boards and pantographs. In the first lesson, students investigate different ironing board leg lengths and pivot positions using similar and congruent triangles. In the second lesson, they use their knowledge of parallelogram ...

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reSolve: Monte Carlo Simulations

This sequence of two lessons explores how statistical techniques that rely on randomly generated data can be used to solve problems. In the first lesson, students compare different methods for calculating the area of an irregular shape, using the context of oil spill maps. They are introduced to the Monte Carlo method for ...

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reSolve: Pythagoras' Theorem - Lunch Lap

In this sequence of two lessons, students apply Pythagoras' Theorem to explore a practical problem involving optimising paths to lunch carts. In the first lesson, students investigate the length of a path that touches three sides of a rectangle, starting and finishing at the same point. They model the problem, use Pythagoras' ...

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reSolve: Tree Biomass

In this sequence of two lessons, students investigate how many trees would be required to supply paper for their school for a year. Students use similar triangles, Pythagoras' Theorem and algebra to design and construct a Biltmore stick, used to measure the diameter and height of a tree. They measure trees, calculate their ...

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reSolve: Pythagoras' Theorem - Phone finding

This lesson challenges students to apply Pythagoras' Theorem to explore a practical real-world problem. Students explore technology reliant on mathematical concepts. The lesson is outlined in detail including curriculum links, vocabulary, materials needed, sample answers, discussion points and student resources such as ...

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 ...

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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.  

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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

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 ...

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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.

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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.

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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 ...

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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 ...

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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.