Performing and Describing Transformations

Scheme of work: GCSE Higher: Year 9: Term 5: Performing and Describing Transformations

Use conventional terms and notations: points, lines, vertices, edges, planes, parallel lines, perpendicular lines, right angles, polygons, regular polygons and polygons with reflection and/or rotation symmetries;
Identify an order of rotational and reflective symmetry for two dimensional shapes
Use the standard conventions for labelling and referring to the sides and angles of triangles; draw diagrams from written description
Recognise linear functions in the form y = ± a and x = ± a

Identify, describe and construct congruent and similar shapes, including on coordinate axes, by considering rotation, reflection, translation and enlargement (including fractional and negative scale factors)

An object is transformed to create an image.
Rotation, Translation and Reflections involve congruent objects and images whereas enlargement leads to the object being similar to the image.
Translation vectors are used to describe movements along Cartesian axes.
When reflecting objects the image is always the same distance from the line of reflection as the object.
Rotations and enlargements are constructed from a centre.
A negative scale factor transforms the object through the centre.

Translation vectors can incorrectly be written using the name notation as coordinate pairs.
Translations, Rotations, Enlargement and Reflections all come under the umbrella term of transformation. Students often confuse the term translation for transformation.
Students often have more difficulty describing single transformations rather than performing them.
Enlargements can involve making a shape smaller as well as bigger. Fractional scale factors between 0 and 1, not negative, decrease the size.