Scale factor enlargement
Shapes A, B, C and D are all similar.
They are indentical in shape but are all different sizes.
B, C and D are all enlargements of shape A.
How much a shape has been enlarged by depends on its scale factor.
How does a scale factor work?
A scale factor tells us by how much a shape has been enlarged.
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.
Question
What scale factor of enlargement do you think describes the larger square compared to the smaller square?
The larger square is an enlargement of the smaller square by a scale factor of 2. Its sides are twice as long as those of the small square.