# Maths - Key Stage 3 (11-14 year olds)

# Geometry and Measures

A superb resource on circles with two sections 'Explore It' and 'Use It' which cover the facts about circle geometry, multiple choice questions with guidance if you go wrong, investigations of circle properties with interactives and game to play.

Exploring the Diameter and Circumference of Circles FlashA multimedia video interactive which shows how circles are found around us and the relationship between circumference and diameter. There is an interactive activity where students can explore the value of pi and a printable worksheet.

Finding Area and Perimeter of Circles FlashAn excellent video tutorial which explains how to find the area and circumference of a circle and a semi-circle.

Axial Symmetry FlashA simple demonstration of what axial symmetry is. View simple shapes and see the difference between horizontal, vertical and diagonal axes.

Symmetry FlashA good tutorial with audio to help pupils learn the names of different polygons and how to draw lines of symmetry on some of them.

What's my Angle FlashA great way to learn how to use a protractor. There's a tutorial on its use and random examples to practise.

Angle Types FlashA simple lesson on acute, obtuse and reflex angles with an interactive test so you can check your understanding.

Angle Types Simulation FlashLearn how to recognise different types of angles: acute, obtuse and reflex in this interactive simulation. You can create the angles on the protractor.

Exploring and Solving Triangles FlashThis website includes a video which shows triangles in everyday life and interactive exercises where students need to find triangles in a picture and then solve all the missing angles. It also includes a printable worksheet.

Quadrilateral Quest FlashA quiz on the properties of shapes.

Translating Shapes FlashAn excellent video tutorial which shows you how to translate a shape using a vector.

Pentominoes FlashThis teaching unit from NGfL Cymru has 12 mini activities on pentominoes. After finding the pentaminoes in the investigation the activities include finding the symmetry and rotational symmetry of the shapes.

Nets of Polyhedra FlashView nets of various solid shapes: tetrahedron, cube, square-based pyramid, cuboid, hexagonal prism, octahedron, triangular prism, dodecahedron and icosahedron.

Tetrahedra Investigation FlashAn investigation using the net of a tetrahedron. See how many ways this can be coloured in using four different colours only once. There are teachers' notes and an accompanying worksheet.

Co-ordinates, Lines and Curves FlashThis site has a series of Microsoft Excel spreadsheets, each with teachers' notes, which can help with graph work.

Random Trigonometry Problems FlashA clever website which generates an endless sequence of trigonometry problems in right-angled triangles. Find either angles or sides. It includes an optional on-screen calculator and provides the solution where you can check your answer.

Analyse Triangular Prisms Lesson Part 1 Not FlashIn this lesson you will learn how to analyse triangular prisms by locating and assessing pairs of congruent triangular faces. Best in full-screen mode.

A Tangled Web Not FlashHelp Itzi the spider rescue his family by solving the angles puzzles. Progressive levels from angles basics, angels between parallel lines, angles in quadrilaterals, polygons and circles.

Best Maths Animated Gifs Not FlashView online or download animated gifs which demonstrate mathematical concepts such as Pythagorus Theorem, how to find the area of a cylinder and more.