lesson

Describe the whole transformation

1 · Learn

A translation needs a displacement, a reflection needs a mirror line and a rotation needs a centre, angle and direction. These transformations preserve lengths and angles. An enlargement changes lengths according to its scale factor.

A picture of the result alone may not specify a unique transformation. Describe all required information and check several corresponding points, not just one.

Translation: displacementReflection: lineRotation: centre/angle/directionEnlargement: centre/factor
Key words and supplied examples.

2 · Worked example

Reflecting (3,-2) across the y-axis gives (-3,-2). Translating the original by 2 left and 5 up instead gives (1,3).

3 · Your turn

Reflect (-4,3) across the x-axis, then translate the reflected point 6 right and 1 down.

Check your answer

The reflection is (-4,-3); the final point is (2,-4).

4 · Apply your learning

Use triangle A(1,1), B(3,1), C(1,2). Reflect the whole triangle in the x-axis, then translate that image 2 right and 3 up. Give every final vertex and verify the length of the image of AB, not just the position of A.

Adult guidance and safety

Require a reasoned method and an independent check. Use accurate number lines, geometric drawings and data displays where the task needs them. These text models require varied practice and diagnostic assessment before curriculum approval.

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Check a calculation · Year 5 onward

Use this only when your teacher or adult allows a calculator for the task. Show your thinking first. It does not replace mental or written arithmetic and does not mark your lesson answer.

Powers, roots and trigonometry · Year 7 onward

Use only when the task allows a calculator. Choose one operation at a time and record your working. Trigonometry here always uses degrees (DEG), not radians. Inverse sine, cosine and tangent return an angle, not a reciprocal. Keep exact fractions and π in answers when requested.

Approximate numerical results use up to 12 significant digits. Inverse sine returns −90° to 90°, inverse cosine 0° to 180°, and inverse tangent −90° to 90°; these are principal values, not every possible solution of a trigonometric equation.

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