Key learning points

1. An enlargement means the object and image are similar.
2. All lengths in the object have been multiplied by the scale factor.
3. Using index laws, this means the area has been multiplied by the scale factor squared.

Keywords

• Similar - Two shapes are similar if the only difference between them is their size. Their side lengths are in the same proportions.

• Invariant - A property of a shape is invariant if that property has not changed after the shape is transformed.

• Enlargement - Enlargement is a transformation that causes a change of size.

• Scale factor - A scale factor is the multiplier between similar shapes that describes how large one shape is compared to the other.

Common misconception