How is the scale factor obtained?

The scale factor can be obtained by dividing the length of a side in the second shape by the length of the corresponding side. The scale factor is a fraction or decimal number that can be used to scale up or down a shape.

A scaled up or scaled down shape is identical to the original shape in terms of number of sides and size of internal angles. The original and scaled shape can be matched up based on the equivalent angles. The scale factor is calculated dividing a side on the resulting shape by the matching side on the original. The lengths of other sides on the scaled shape can be calculated by multiplying other sides of the original by the scale factor.