Geo 4.5 Dilations

Front

What is the scale factor in a dilation?

Back

The scale factor is the ratio of a length of the new figure to the corresponding length on the original figure.

Front

If a rectangle with vertices at (2, 2), (2, -2), (-2, -2), and (-2, 2) is dilated by a scale factor of 2 with the origin as the center of dilation, what are the new coordinates?

Back

(4, 4), (4, -4), (-4, -4), (-4, 4)

Front

What are the new coordinates of a triangle with vertices (2,0), (3,-1), and (-2,-5) when dilated by a scale factor of 3 with the origin as the center of dilation?

Back

(6,0), (9,-3), (-6,-15)

Front

What happens to the coordinates of a line segment when a dilation with a scale factor of 0.75 is applied?

Back

The new coordinates of endpoints A(4, 4) and B(8, 8) become A'(3, 3) and B'(6, 6).

Front

What does a scale factor of less than one indicate?

Back

It indicates that the image will be a reduction of the pre-image.

Front

Define dilation in geometry.

Back

Dilation is a transformation that produces an image that is the same shape as the original, but is a different size.

Front

What is the center of dilation?

Back

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

Front

How do you calculate the new coordinates after dilation?

Back

Multiply each coordinate of the original figure by the scale factor.

Front

What is the effect of a scale factor greater than one?

Back

The image will be larger than the pre-image.

Front

If a point (x, y) is dilated by a scale factor k, what are the new coordinates?

Back

The new coordinates will be (kx, ky).