Mathematics / Year 8 / Measurement and Geometry / Geometric reasoning

Curriculum content descriptions

Develop the conditions for congruence of triangles (ACMMG201)

Elaborations
  • investigating the minimal conditions needed for the unique construction of triangles, leading to the establishment of the conditions for congruence (SSS, SAS, ASA and RHS)
  • solving problems using the properties of congruent figures
  • constructing triangles using the conditions for congruence
General capabilities
  • Numeracy Numeracy
ScOT terms

Congruence (Geometry),  Triangles (Shapes)

Text

Geometric reasoning - congruence

This is a website designed for both teachers and students that introduces congruence of shapes in the plane through transformations. In particular, transformations, translations, reflections in an axis and rotations of multiples of 90 degrees are used to define congruence and to identify congruent shapes. The four congruence ...

Text

Making triangles

In this lesson, students study the concept of triangle inequality, which determines if three positive numbers can serve as the side lengths of a triangle. Students experiment with various combinations of three natural numbers. They investigate whether these numbers can form a triangle and classify and construct the corresponding ...

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

MathXplosion, Ep 33: On the grid

Explore graphs, grids and mapping with a focus on reading and writing location data using coordinate geometry. Grids and maps illustrate the concepts of parallel/perpendicular lines (axes or labelled number lines), ordered pairs and intersection points.

Video

Comparing fuel consumption

Is it more fuel efficient to drive or fly between two places? Watch this clip and learn how to calculate the answer. What are the various factors that need to be taken into account? This video was made using the American measurement of gallons per hour, American firgures for the average number of passengers in a car and ...

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

Syllabus bites – speedy sliding

This is the first in a series of Syllabus bites related to transformations on the Cartesian plane aimed at Stage 4 Mathematics. Students find the coordinates of image points after translation. In doing so, they develop fluency in using coordinates and familiarity with the Cartesian plane, providing a basis for the investigations ...

Interactive

Syllabus bites – flipping and sliding

This is the third in a series of Syllabus bites related to transformations on the Cartesian plane. Students further their understanding of translation and reflection and explore relationships between these two transformations.

Interactive

Numeracy wrap: Tell me why

Interactive activities that guide students to consider the use and presentation of geometric reasoning.

Interactive

Syllabus bites – mixing it up

The fifth in a series of Syllabus bites related to transformations on the Cartesian plane. This bite covers combinations (composition) of transformations.

Video

Are plants mathematicians?

Ever noticed that plants are examples of Fibonacci numbers? Watch Vi Hart draw examples of flower petals and leaf growth that follow this pattern. See how plants seem to use Phi (.), the golden ratio. Find out how to make your own 'angle-a-tron' to create interesting petal designs. This is the second in a series of two.

Interactive

Syllabus bites – turbo turning

The fourth in a series of Syllabus bites related to transformations on the Cartesian plane. This Bite covers rotation of points.

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

What are pixels?

Meet Kevin Systrom and Piper Hanson as they explain how digital images work. What are pixels, those tiny dots of light, made from? How are colours created and represented? What does Kevin say about the way mathematical functions are used to create different image filters. What is the difference between image resolution ...

Interactive

Desmos Graphing Calculator - Google Play app

Plot functions, create tables, add sliders and animate your graphs. Touch points of interest on the graph to show maximums, minimums and points of intersection. Type in an equation and watch the calculator solve the problem.

Text

TIMES Module 17: Measurement and Geometry: the circle - teacher guide

This is a 15-page guide for teachers. In the module the formulas for finding the circumference and area of a circle are introduced. The history and significance of the number pi is also included in this module.

Text

Plotting linear relationships and examples of linear relations

This is a website designed for both teachers and students, which addresses content on plotting linear relationships from the Australian Curriculum for year 8 students. It contains material on plotting points on the Cartesian plane, working with tables of values, and looking at the gradient and the equation of a line. There ...

Text

Circles

This is a website designed for both teachers and students that refers to the properties of circles including the circumference and area from the Australian Curriculum for year 8 students. It contains material on finding circumferences and areas of circles, and the areas and perimeters of shapes formed from circles and other ...

Text

Volumes of prisms

This is a website designed for both teachers and students that refers to volumes of prisms and using formulas to find the volumes of prisms. It contains material on rectangular and triangular prisms and finding the volumes of these by using formulas. There are pages for both teachers and students. The student pages contain ...

Text

The Geometry and Algebra of Honeycomb - Calculate

This integrated unit of work explores the amazing structures of honeycomb by examining the properties of regular and irregular polygons and polyhedra. Students then move on to solve problems using geometric and algebraic reasoning.