Geometry - Dilation & Similarity

Front

What is dilation in geometry?

Back

Dilation is a transformation that alters the size of a figure but maintains its shape, using a scale factor.

Front

What does a scale factor greater than 1 indicate in dilation?

Back

It indicates an enlargement of the figure.

Front

What does a scale factor less than 1 indicate in dilation?

Back

It indicates a reduction or shrinkage of the figure.

Front

How do you write the algebraic notation for a dilation with a scale factor of 1/2?

Back

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

Front

What is the relationship between similar figures?

Back

Similar figures have the same shape but may differ in size; their corresponding angles are equal and their corresponding sides are proportional.

Front

If two triangles are similar, how can you find a missing side length?

Back

Use the ratio of the lengths of corresponding sides to set up a proportion.

Front

What is the scale factor from triangle ΔDEF to triangle ΔABC if the sides of ΔDEF are half the length of those in ΔABC?

Back

The scale factor is 1/2.

Front

What is the formula for finding the area of similar figures?

Back

The area ratio of two similar figures is equal to the square of the ratio of their corresponding side lengths.

Front

If the scale factor is 3, how does the area of the dilated figure compare to the original?

Back

The area of the dilated figure is 9 times the area of the original figure.

Front

What is the effect of a negative scale factor in dilation?

Back

A negative scale factor reflects the figure across the origin and changes its size.