# Year 9, Unit 2 – working with triangles

The lessons and sequence in this unit are designed to allow students to use the properties of right-angled triangles to solve a range of geometrical, measurement and real world problems.

This program of learning addresses content from the focus areas Trigonometry A, Linear relationships A, Numbers of any magnitude, as well as Path focus areas Linear relationships C, and Indices C.

The Mathematics K–10 syllabus (2023) is to be taught in Years 3 to 10 from 2024.

Detailed implementation information including key features and resources is available on the Mathematics syllabus development page (NESA).

### Working with triangles

Working with triangles is a 16-lesson unit for Year 9 with resources.

#### Introduction

Working with triangles (DOCX 162 KB)

#### Lesson 5 – I lost my calculator

I lost my calculator (DOCX 102 KB)

#### Lesson 8 – mapping the classroom

Mapping the classroom (DOCX 7.1 MB)

#### Lesson 9 – surd is the word

Surd is the word (DOCX 125 KB)

#### Lesson 10 – distances

Distances (DOCX 647 MB)

#### Lesson 11 – midpoints

Midpoints (DOCX 510 KB)

#### Lesson 12 – trigonometry for navigation

Trigonometry for navigation (DOCX 1.2 MB)

#### Lesson 15 – slopes as gradients

Slopes as gradients (DOCX 1.9 MB)

#### Lesson 16 – gradients in the Cartesian plane

Gradients in the Cartesian plane (DOCX 298 KB)

Syllabus outcomes and content descriptors from Mathematics K–10 Syllabus © NSW Education Standards Authority (NESA) for and on behalf of the Crown in right of the State of New South Wales, 2023.