Similar and Congruent Figures

Front

What are similar figures?

Back

Figures that have the same shape but not necessarily the same size. Their corresponding angles are equal and the ratios of their corresponding side lengths are proportional.

Front

What does it mean for two figures to be congruent?

Back

Two figures are congruent if they have the same shape and size. All corresponding sides and angles are equal.

Front

Are all corresponding angles in similar figures congruent?

Back

True

Front

If ΔABC ≅ ΔXYZ, what can we say about the angles?

Back

∠C ≅ ∠Z (corresponding angles in congruent triangles are equal).

Front

What is the relationship between the side lengths of similar figures?

Back

The ratios of the lengths of corresponding sides are equal.

Front

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

Back

Set up a proportion using the lengths of corresponding sides and solve for the missing length.

Front

What is the term for two figures that are the same shape but not the same size?

Back

Similar.

Front

If the ratio of the sides of two similar triangles is 2:3, what is the ratio of their areas?

Back

The ratio of their areas is 4:9 (the square of the ratio of the sides).

Front

What is a proportion?

Back

An equation that states that two ratios are equal.

Front

How do you determine if two figures are similar?

Back

Check if all corresponding angles are equal and the ratios of corresponding sides are equal.