Dilations and Similarity

Front

What is Dilation?

Back

Dilation means to enlarge or reduce a figure in size while maintaining its shape.

Front

What does a scale factor greater than 1 indicate?

Back

A scale factor greater than 1 indicates that the prime image will be larger than the pre-image.

Front

What does a scale factor of less than 1 indicate?

Back

A scale factor of less than 1 indicates that the prime image will be a reduction of the pre-image.

Front

If a triangle has vertices A(0,0), B(8,0), C(3,-2), what are the coordinates after a dilation with a scale factor of 4?

Back

A(0,0), B(32,0), C(12,-8)

Front

Are the triangles with vertices A(0,0), B(8,0), C(3,-2) and A'(0,0), B'(32,0), C'(12,-8) similar?

Back

No, they are not similar because they are not the same shape.

Front

What is the scale factor if the image is twice the size of the original?

Back

The scale factor is 2.

Front

How do you calculate the coordinates of a point after dilation?

Back

Multiply the x and y coordinates of the point by the scale factor.

Front

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

Back

A scale factor of 1 means the figure remains the same size.

Front

If a shape is dilated by a scale factor of 1/2, what happens to its size?

Back

The shape is reduced to half its original size.

Front

What is the relationship between similar figures?

Back

Similar figures have the same shape but may differ in size.