Search results

Refine results by

Year level
Resource type
Learning area
Listed under:  Mathematics  >  Geometry  >  Shapes (Geometry)  >  Polygons  >  Triangles (Shapes)
Video

Pythagoras's theorem: proof

This learning object includes animations of transformational geometry and algebraic proofs of Pythagoras's theorem. Interactive Illustrations of the theorem, worked examples, a quiz and practice questions are included.

Teacher resource

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.

Teacher resource

TIMES Module 14: Measurement and Geometry: congruence - teacher guide

This is a 30-page guide for teachers. It contains an introduction to congruence, in particular the congruence tests for triangles. Applications of congruence are included throughout the module.

Teacher resource

Starting Smart: how are shapes and objects related?

This curriculum resource package is a ten-week middle years teaching plan and set of supporting resources to extend students' understanding of geometrical language and spatial relationships. Students use concrete materials and interactive geometry software packages to compare and describe geometrical attributes and investigate ...

Moving Image

Applying trigonometry: leaning tower

The Leaning Tower of Gingin is the centrepiece of the Gravity Discovery Centre. The Catalyst team of Derek, Simon and Anja drop watermelons from the tower, to examine the rate at which they fall. They are testing Galileo's theory about falling objects. The dimensions of the tower provide an opportunity to apply some basic ...

Moving Image

Mapping farmland: using area and trigonometry

In northern Queensland's Gulf region, some farmers use GPS mapping to help manage their extensive properties. Use this clip as a context for applying your understanding of area, in particular your understanding of conversion between square kilometres and hectares. Apply trigonometry and Pythagoras' theorem.

Moving Image

Space debris: the accuracy of space lasers

In space there are thousands of human-made objects (satellites and space junk) orbiting Earth. To avoid collision with space debris, satellites are manoeuvred out of its path. Discover how space debris is tracked using lasers, and about accuracy's effects on the lifetime of the satellite. Find out, using trigonometry, the ...

MovingImage

Triangle Types

An interactive applet in which students classify triangles as isosceles, scalene and equilateral.

Moving Image

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 resource

Area of triangles

Find the area of different types of triangles on a grid. Explore how the formula works. First, estimate the area of a chosen triangle on a grid. Next, work out the correct formula by assembling a series of triangles and rectangles. Then, compare the actual area of the triangle with your original estimate. Practise applying ...

Interactive resource

Measures: similar shapes

Compare the sizes and angles of a range of triangles, squares and rectangles. Notice that 'similar shapes' in the mathematical sense have the same shape and possibly different sizes. Corresponding sides are in proportion, and corresponding angles are equal. Identify shapes that are similar and create shapes similar to given ...

Interactive resource

Measures: scaling up

Compare the areas of squares, rectangles and triangles before and after being scaled up (enlarged). Notice that 'similar shapes' in the mathematical sense have the same shape but different areas. Explore the relationship between side-length enlargement and area enlargement when scaling up shapes. This learning object is ...

Interactive resource

Measures: scaling down

Compare the areas of squares, rectangles and triangles before and after being scaled down (reduced). Notice that 'similar shapes' in the mathematical sense have the same shape but different areas. Explore the relationship between side-length reduction and area reduction when scaling down shapes. This learning object is ...

Interactive resource

Congruent triangles

Find out about congruent and non-congruent triangles and the conditions required to make them. Use line segments and angles to build two congruent triangles for three different combinations of sides and angles. Explore the SSS case (side, side, side), the SAS case (two sides and the included angle) and the ASA case (two ...

Interactive resource

Area of triangles: height intersects with the base inside the triangle

Find the area of triangles that have vertical or horizontal sides. In this type of triangle, the height intersects with the base inside the triangle. Explore how the formula for finding the area of a triangle works. First, estimate the area of a chosen triangle on a grid. Next, work out the correct formula by assembling ...

Interactive resource

Area of triangles: height intersects with the base outside the triangle

Find the area of triangles with vertical or horizontal sides. In this type of triangle, the base may be chosen so that the height intersects with the base outside the triangle. Explore how the formula for finding the area of a triangle works. First, estimate the area of a chosen triangle on a grid. Next, work out the correct ...

Interactive resource

Area of triangles: triangles without vertical or horizontal sides

Find the area of triangles that do not have vertical or horizontal sides. Explore how the formula works. First, estimate the area of a chosen triangle on a grid. Next, work out the correct formula by assembling a series of triangles and rectangles. Then, compare the actual area of the triangle with your original estimate. ...

Interactive resource

Exploring angles

Resize a triangle by moving its vertices. Notice that the sum of the three interior angles is always 180 degrees. Watch a video showing how angles are used in designing and riding bicycles.

Interactive resource

Exploring triangles

Find an active triangle in a photograph. Work out its angles by applying principles of opposite angles, complementary angles, supplementary angles and the sum of interior angles. Watch a video showing how triangles are used in buildings and other structures.

Assessment resource

Area of triangles: assessment

Test your understanding of how to use the formula for calculating the area of triangles. Find the area of nine different triangles on a grid. First, predict the area of a chosen triangle on a grid. Find the base and height measurements of the triangle using an animation. Then, substitute the base and height measurements ...