Section 8.1 – Dilations and Scale Factors

REVIEW: Transformations à Translation (slide), Reflection, Rotation

Same size, same shape – Rigid

Dilation – a transformation that is not rigid

Preserve shape, but may change its size

Dilation in coordinate plane can be found by multiplying the x- and y-coordinates of a point by the same number, n.

D(x ,y) = (nx, ny)

Scale factor – the number, n, used to multiply in a dilation

If n > 1, the dilation is an expansion

If n < 1, the dilation is a contraction

Center of dilation – the point from which the dilation is originated. In a coordinate plane, it is usually the origin.