Similarity

Front

What does it mean for two figures to be similar?

Back

Two figures are similar if they have the same shape but not necessarily the same size. Their corresponding angles are congruent, and their corresponding sides are in proportion.

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6

Front

What is a scale factor?

Back

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

Tags

CCSS.7.G.A.1

Front

If the scale factor is greater than 1, what happens to the figure?

Back

The figure undergoes an enlargement.

Tags

CCSS.8.G.A.3

Front

If the scale factor is less than 1, what happens to the figure?

Back

The figure undergoes a reduction.

Tags

CCSS.8.G.A.3

Front

What happens to the angles of similar figures?

Back

The angles of similar figures are congruent.

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6

Front

What happens to the sides of similar figures?

Back

The sides of similar figures are proportional.

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6

Front

How do you find the missing side of a similar figure?

Back

Use the ratio of the corresponding sides and the scale factor to set up a proportion and solve for the missing side.

Tags

CCSS.7.G.A.1

Front

What is dilation in geometry?

Back

Dilation is a transformation that alters the size of a figure but keeps its shape, making it larger or smaller.

Tags

CCSS.8.G.A.3

Front

What is the relationship between the scale factor and the area of similar figures?

Back

The area of similar figures is proportional to the square of the scale factor.

Tags

CCSS.7.G.A.1

Front

If triangle A is similar to triangle B with a scale factor of 3, what is the ratio of their areas?

Back

The ratio of their areas is 3^2 = 9.