Mathematics / Year 9 / Measurement and Geometry / Using units of measurement

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Curriculum content descriptions

Calculate areas of composite shapes (ACMMG216)

Elaborations
  • understanding that partitioning composite shapes into rectangles and triangles is a strategy for solving problems involving area
General capabilities
  • Numeracy Numeracy
ScOT terms

Area,  Polygons

Interactive resource

Exploring area and perimeter

Build a compound shape on a grid from shapes such as rectangles, semicircles and squares. Notice that the total area of the compound shape equals the sum of the areas of all of the component shapes. Build a rectangle to produce a given area and perimeter. Identify shapes used to form a compound shape. Calculate the area ...

Moving Image

Area of composite shapes

Finding the area of a rectangle is quite easy. But what if the shape you're working with is not a simple rectangle? What if it's a composite shape made up of two different-sized rectangles? See how to work out the area, and discover why you need to use the same units.

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BBC Bitesize: area - revision

This is a set of illustrated information sheets about the concept of area, and formulas for the calculation of areas of rectangles, triangles, parallelograms and compound shapes. Examples with answers are included and students have access to test questions to assess their learning. This resource is one of a series of online ...

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.

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BBC Bitesize: compound shapes - revision

These illustrated information sheets revise ideas about area of triangles, rectangles, parallelograms and compound shapes. Examples with answers are included and students have access to a multiple-choice test to assess their learning. This is one of a collection of BBC-produced learning objects in the Bitesize series dealing ...

Interactive resource

Measures: scaling surface area

Compare the surface area of cubes and rectangular prisms before and after being scaled up (enlarged) or scaled down (reduced). Notice that 'similar shapes' in the mathematical sense have the same shape but different surface areas. Explore the relationship between side length and surface area when scaling solids. This learning ...

Interactive resource

Exploring square roots

Build a square on a grid to cover a given number of units. Notice that each side of the square equals the square root of the area. Calculate the area of each square and work out the square root. For example, calculate the length of each side needed for a square to cover 81 units. Calculate the area of squares bordering ...

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: volumes

Compare the volumes of a range of rectangular prisms when scaling up (enlarging) side lengths by different ratios. Notice that the rectangular prisms are not similar in the mathematical sense, but it is possible to predict the effect on the volume produced by the scaling of the sides. Identify and describe the relationship ...

Interactive resource

EagleCat: scale it

Explore changes in area when a shape is acted on by a scale factor. Examine changes in volume when an object is acted on by a scale factor. Analyse the changes using whole numbers.

Interactive resource

Exploring the Pythagorean theorem

Adjust the dimensions of a right-angled triangle. Calculate the area of squares bordering each side of the triangle. Notice that the area of the square bordering the hypotenuse is equal to the sum of the areas of the squares bordering the other two sides. Watch a video showing how Pythagoras's theorem is used to determine ...

Teacher resource

Turn up the volume - unit of work

In this unit of work students explore and explain the connections between the surface area and volume of different shapes and how each attribute is measured.

Teacher resource

Dart probability

In this mathematical activity, students calculate expected scores for a novice dart player. They use technology to determine the best section to aim for and use areas to weight scores to account for double and triple scores.

Interactive Resource

Surface area of prisms

This is a five-page HTML resource about solving problems concerning surface areas of prisms. It contains one video and five questions, two of which are interactive. The resource discusses and explains solving problems involving determining surface areas of prisms to reinforce students' understanding.

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

Measures: scaling up solids

Compare the volumes of cubes and rectangular prisms before and after being scaled up (enlarged). Notice that 'similar solids' in the mathematical sense have the same shape but different volumes. Explore the relationship between side length and volume when scaling up solids. This learning object is the fifth in a series ...

Interactive resource

Measures: scaling down solids

Compare the volumes of cubes and rectangular prisms before and after being scaled down (reduced). Notice that 'similar solids' in the mathematical sense have the same shape but different volumes. Explore the relationship between side length and volume when scaling down solids. This learning object is the sixth in a series ...

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.

Interactive Resource

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.

Interactive resource

Exploring ratios and proportions

Explore ratios by comparing the dimensions of two rectangles. Choose a scale to enlarge the smaller shape and identify whether its sides are proportional to those of the larger rectangle. For example, a rectangle with sides in the ratio 4:5 has an equivalent ratio to a rectangle with sides in the ratio 12:15. Watch a video ...