IGCSE Maths / Transformation and similarity

Similarity under enlargement

Edexcel International GCSE Maths (4MA1), chapter 14: Transformation and similarity, specification point 5.2k. Part of the full course.

Read the revision notes · IGCSE Maths past papers

An enlargement changes a shape’s size but keeps its angles the same. Matching lengths scale by k, so the shapes are similar and their areas scale by k².

More lessons in Transformation and similarity

• Lines of symmetry and rotational symmetry
• Equations of common mirror lines
• Reflecting a shape in a line
• Reflecting in y = x and y = -x
• Finding the mirror line from object and image
• What defines a rotation
• Rotating a shape about a point
• Positive and negative rotation angles
• Rotating about a point not on the shape
• What defines a translation
• Translating a shape
• Column vectors in translations
• Congruence under transformations
• Describing a single transformation fully
• Combining two transformations
• What defines an enlargement
• Enlarging from a given centre
• Fractional scale factor enlargements
• Finding the centre of enlargement
• Conditions for congruent triangles
• Proving triangles are congruent
• Similar shapes: corresponding lengths
• Area scale factor
• Volume scale factor
• Similar solids, mass and capacity
• Similar shapes problem solving