Scale factor enlargement

Shapes B, C and D are all enlargements of shape A.

They are all different sizes. However, we say that they are all similar shapes.

Scale factor enlargement

Scale factor

When describing enlargements you must state by how much the shape has been enlarged. This is called the scale factor.

For example, a scale factor of {2} means that the side-lengths of the new shape are twice the side-lengths of the original. A scale factor of {3} means that the side-lengths of the new shape are three times the side-lengths of the original.