# Mathematics / Year 7 / Measurement and Geometry / Geometric reasoning

Curriculum content descriptions

Classify triangles according to their side and angle properties and describe quadrilaterals (ACMMG165)

Elaborations
• identifying side and angle properties of scalene, isosceles, right-angled and obtuse-angled triangles
• describing squares, rectangles, rhombuses, parallelograms, kites and trapeziums
General capabilities
• Literacy Literacy
• Numeracy Numeracy
ScOT terms

Angles,  Triangles (Shapes),  Sides (Polygons)

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Year level 7-8
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Learning area Mathematics

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Related topic

Examine the sides and angles of a four-sided shape. Identify its geometric properties such as the number of sides of equal length. Classify the shape as a parallelogram, rhombus, square, rectangle, kite or trapezium. Notice that some quadrilaterals can be classified in different ways.

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### BBC Bitesize: angles - revision

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### Numeracy wrap: It's what's inside that counts

interactive activities that guide students to explore the interior and exterior angle sums of polygons.

### Exploring angles

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### Exploring relationships of angles

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### 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 ...

### 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 ...

### HOTmaths: exploring kites

Use a tool to explore and identify the properties of kites. For example, investigate angles, side lengths and the lengths of diagonals in kites.

### 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 ...

### 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 ...

### 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. ...

### The amazing 'angle-a-tron'

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### Renovate, Calculate!

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### Geometric reasoning including parallel lines and angle sum of a triangle

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### 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 ...

### The geometer's warehouse

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