Mathematics / Year 9 / Measurement and Geometry / Geometric reasoning

• TLF-IDM013360

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 ...

• TLF-IDM009166

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.

• TLF-IDA010082

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 ...

• TLF-IDA004303

This unit of work explores coordinate geometry in the context of Voronoi diagrams. Students use linear coordinate geometry to construct Voronoi diagrams by finding the gradient of a line segment, then finding the midpoint, a perpendicular line and finally the perpendicular bisector.

• TLF-IDM025322

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 ...

• TLF-IDM025323

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' ...

• TLF-IDM021843

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 ...

• TLF-IDM017688

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 ...

• TLF-IDM016249

Students construct a series of GeoGebra applets that investigate the parameters gradient and intercepts of straight lines. They reinforce this knowledge with Microsoft Math 3.0. 

• TLF-IDM016265

Distance, midpoint and gradient are investigated as students design an Excel spreadsheet and make a Smart Notebook presentation on ski-lifts. Students then contribute to a discussion on the steepest street in the world.