Scale factor and dilations

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, some quantity. In geometry, it is the ratio of the lengths of two corresponding sides of two similar figures.

Front

What happens to a figure when it is dilated by a scale factor greater than 1?

Back

The figure is enlarged.

Front

What happens to a figure when it is dilated by a scale factor less than 1?

Back

The figure is reduced.

Front

What is the center of dilation?

Back

The center of dilation is a fixed point in the plane about which all points are expanded or contracted.

Front

If the coordinates of a point are (x, y), how do you find the coordinates after a dilation by a scale factor of k?

Back

The new coordinates will be (kx, ky).

Front

What is the result of dilating the point (2, 3) by a scale factor of 3?

Back

The new coordinates will be (6, 9).

Front

What is the relationship between similar figures?

Back

Similar figures have the same shape but different sizes.

Front

How do you express a dilation with a scale factor of 1/2 in algebraic notation?

Back

(x, y) goes to (1/2x, 1/2y).

Front

What is the effect of a scale factor of 1 on a figure?

Back

The figure remains unchanged.

Front

What is the term for a transformation that produces a figure that is the same shape as the original but a different size?

Back

Dilation.