Scale factor
Triangles that have been enlarged or reduced by the same amount are always similar. The ratio of the
side lengths is called the scale factor.
By measuring, find the scale factor that has been used in each pair of similar triangles.
Triangle
Side 1
Side 2
Side 3
ABC
Side 2
Side 3
Side 1
Side 2
Side 3
A 2B 2C 2
nd
So 2 triangle is ……………………… and
the scale factor is …………………
Triangle
A 1B 1C 1
A 1B 1C 1
A 2B 2C 2
ABC
nd
So 2 triangle is ………………..…… and
the scale factor is …………………
Triangle
Side 1
ABC
A 1B 1C 1
nd
So 2 triangle is enlarged and
the scale factor is …………………
Triangle
Triangle
Side 1
Side 2
Side 3
A 2B 2C 2
ABC
nd
So 2 triangle is ………………..…… and
the scale factor is …………………
Side 1
Side 2
Side 3
nd
So 2 triangle is ……………………… and
the scale factor is …………………
Triangle
Side 1
Side 2
Side 3
A 2B 2C 2
A 1B 1C 1
nd
So 2 triangle is ……………………… and
the scale factor is …………………