Similar Figures

Front

What are similar figures?

Back

Figures that have the same shape but not necessarily the same size.

Front

What does 'corresponding' mean in geometry?

Back

It means matching, referring to sides or angles that are in the same relative position in similar figures.

Front

If two triangles are similar, what can we say about their angles?

Back

Their corresponding angles are equal.

Front

If two figures are similar, what can we say about their sides?

Back

Their corresponding sides are in proportion.

Front

What is the scale factor in similar figures?

Back

The ratio of the lengths of corresponding sides of two similar figures.

Front

If triangle ABC is similar to triangle DEF, what can we say about the lengths of sides AB and DE?

Back

AB/DE = AC/DF = BC/EF (they are proportional).

Front

What is the relationship between the areas of two similar figures?

Back

The ratio of their areas is the square of the ratio of their corresponding side lengths.

Front

If the scale factor of two similar figures is 2:3, what is the ratio of their areas?

Back

The ratio of their areas is 4:9 (since (2^2):(3^2) = 4:9).

Front

What does it mean for two shapes to be congruent?

Back

They are the same shape and size.

Front

If triangle XYZ is similar to triangle ABC, and the length of side XY is 6 cm and side AB is 9 cm, what is the scale factor?

Back

The scale factor is 6:9 or 2:3.